Honda-SOHC
SOHC.co.uk Forums => CB750 => Topic started by: El__burro on October 04, 2014, 12:43:25 PM
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I am curious to see if the engine is in working order (and mainly want to hear it roar)
Is there a way to start it without mounting all the bits and pieces ie coils end the rest of the wiring diagram.
In other words what is the minimum necessary to start it?
Thanks(http://tapatalk.imageshack.com/v2/14/10/04/993ecf2f7ea4bd6cd794b6ba2f29aa63.jpg)
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1st you need coils then battery,Then a positive feed to the coils and points which means you need wiring from the points to the coils.When you have it right the points will spark and so should the plugs
In case of any problems air leaks crap carbs if she revs like hell you need to disconnect the positive feed bloody quick.
Do not think its worth the risk but easy for me I love electrics
Hope this helps, it for me is easier to do it than explain it
Cheers
Bitsa
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Thanks for the reply.
The wiring seems to be there I have a rectangular plug coming out from the engine, then I have the rest of the wiring aside. I need a battery any recommendations for this
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In My opinion get a gel battery seem to be for me great and you get rid off a tube that spews acid on your gorgeous exhausts
Cheers
Bitsa
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I'll go along with Bitsa as to wiring it, but would add that you may need an oil pressure light as well and try to get oil pressure with the plugs out before you try to run it.
Oh and something halfway sensible for oil condition or you risk damaging it.
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My idea was to remove the engine from the frame.
Since i have not much linking it to the frame, as mentioned the wiring is unplugged (and seems to be completed)
I am just trying to get enough to start a bench test.
Fuel, oil, battery and so on.
Is there a link to explain what is needed exactly.
Thanks
El__burro
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Almost there, i have purchased oil and a battery, electrical harness is as new and complete. Just waiting for a good sunny day to attempt.
I am not sure about the condition of the engine inside and i was thinking to flush it somehow...
How?
Thanks
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I would at least take the sump off and check out the pump.
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Out of boredom i have removed the oil sump bolt to check for oil.
Actually almost a litre came off it. Then I tried to add more but it would not go through the engine and out again. It stays in the oil tank. Is this normal? I guess that is what the pump is for.
How much oil do i need to add (from zero) to ensure no damage is done. Bear in mind that I just want to hear it roar.
Thanks
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Just because it has oil coming out of the sump. How do you know if the pump is working and the strainer is not blocked ?
If you have no oil feed to the top end, the cam will not last very long.
Have you kicked it over until the oil light has gone out ?
Opp's for got: Oil capacity is 3.5 ltr with 2ltr of that in the tank. Pump likes to be primed.
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Do what Trig says I would and do
Cheers
Bitsa
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Do what Trig says I would and do
Cheers
Bitsa
Baa-aa ;D
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Do what Trig says I would and do
Cheers
Bitsa
We know,we know
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Good Oh ;D ;D
Bitsa
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Probably today i will remove the oil sump, but how can I tell if the pump works without power?
What wattage is the oil warning light?
Thanks
El__burro
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According to the bikes owners manual 3 watt
Cheers
Bitsa
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This morning between one shower and an other I've managed to assemble part of the wiring.
Unfortunately I couldn't get it to start but I managed to test the starter motor, it sounds good.
Tomorrow I'll have a better look at the wiring
Can the rectifier (in the picture) be rewired somehow from the middle?
(http://tapatalk.imageshack.com/v2/15/01/13/fe320bb17f7ff23ae792e75281a734e7.jpg)
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Nothing.
3 days of attempts have led me to nothing actually, to desperation.
I have followed the wiring diagram but no sign of life.
I have tested the starter relay, works fine.
Replaced the kill switch and start button, still nothing.
It seems like i have no power to that side.
Battery is new and fully charged
I have been trying to test the rectifier but is it worth?
What is the very very basic wiring i need to connect?
Thanks
El__burro
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Rectifer
Will not stop it from starting.Are you sure by the coils you did not connect the blk to blk/white?If you have put them in the blk.Blk/white is stop switch
Cheers
Bitsa
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Bitsa, the 2 black/white wire connect into one and end up to the kill switch.
clymer manual has a wiring diagram for k2 but I think there's something wrong with it. (It has 3 fuses)
(http://tapatalk.imageshack.com/v2/15/01/15/015de7b04659e441c34ca5b5314bda28.jpg)
I am using the one above found online. One fuse as per my wiring.
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Bitsa, the 2 black/white wire connect into one and end up to the kill switch.
clymer manual has a wiring diagram for k2 but I think there's something wrong with it. (It has 3 fuses)
I am using one I found online. One fuse as per my wiring. (attached)
K2's came with a single fuse on the early units and moved on to the 3 fuse.
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Not much but at least a step forward,
After replacing starter and kill switches i have finally managed to operate the starter motor from the push start switch.
Now..
I am looking at COILS, there is no spark on any of the plugs,
I am looking to test the coils, any suggestions?
Thanks
El__burro
i can
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check they have two circuits each,
use a multi meter and connect both plug leads ,you should get a reading,
also the normal cables,check the circuit on those,treat each coil separately ,
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I have done the test suggested above and it gives me continuity when i connect either the blu and black/white or the yellow and the bl/w.
My issue is when i connect the HT leads from the same coil, they both read about 14.0 ohms but no continuity.
Faulty?
Thanks
El__burro
Cb750 k2
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Today I've reset the points just to make sure. Gap was ok while the plate was way off.
Still making the adjustment hasn't given me any sparks.
Also when the starter motor turns I can hear a squeaky noise, is it because it has no oil?
Thanks
http://youtu.be/TwtZYIsBtwk (http:// http://youtu.be/TwtZYIsBtwk)
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Me again, tested both condensers and they are good. Still no sparks. Just seen a spark on the (2-3) plugs when I shorten the 2-3 points to th the frame.
Also, starter motor turns even when I turn off (disconnect the black/wire and black) the kill switch.
Any idea?
Any one?
El__ burro
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Hi El_burro,
Your last sentence (above post) quite correct... the kill switch only kills the ignition (spark) & not the cranking of the starter motor.
You sound to be having a frustrating time, I'm no guru on these bikes but would be trying this if it were mine....
I assume the carbs, fuel, air delivery all upto spec.... waste of time if not. (Fresh petrol... not 5 yrs old with water in it.... fuel filter not clogged etc?) Also battery nicely charged up.
Safety.
I'm suggesting getting the wiring as basic as possible to rule out problems here.... there may be a tiny electrical spark on starting the engine... so please ensure no loose petrol, kids about, tank cap on etc.
What to try.
Using fresh wire, ie bypassing the bike's kill switch can I suggest the following 'test set-up'. (If the starter is cranking fine then leave the heavy duty wires in place, ie those beefy 8mm or so ones)
Run a 'thin' wire from the battery +ve to one side (small post) of the starter solenoid, and to the other solenoid (small post) run another 'thin' wire.... leaving the end loose, but long enough to touch the -ve battery terminal. This will be your starter switch... expect a SMALL spark, nothing scary.
Run a 2nd 'thin' wire (also) from the battery +ve to the coils via a bullet connector. This bullet connector should split into two, and feed both the coils... normally each with a Black / White wire. Each coil, via its other (Blue or Yellow) wire then goes to the contact breaker points, through those, and to earth. (see accompanying pages for points set-up). (Condensers of course must be in place)
The bullet connector mentioned above will be your 'kill switch'.... ie the means of powering the ignition / stopping the engine. Not ideal, but good enough for trouble shooting to rule out other electrical gremlins...
To start the engine..
(1) ensure coils powered via double bullet connector, (terminal B)
(2) crank starter by touching wire A to the battery - ve terminal (or any good earth) (slight spark, after cranking / start ensure A kept away from earth / -ve battery terminal
It took me a while to fathom, but my K2 starts best (on the button) with full choke & Full (WOT) throttle. Yours, may of course be very different.
To stop the engine
(1) Pull bullet connectors (both)
(2) choke (on or off... whatever it takes)
(3) rear brake, assuming in gear & on the centre stand. Be careful! No kids about...
(4) Pair of scissors / pliers to cut the battery lead to bullet connector!
On another thead you mentioned HT coil resistance @ 14 ohms.... if this is the case this coil would appear to be duff.... it should be somewhere in the region of 10-20 K ohms.
If you have a strobe light, this can be a good indication of HT (sparks) output. Check both coils.
Finally, if you're not comfortable with any of the above... don't do it.
Cheers & happy spannering,
Simon
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If you have no spark as you say start from scratch and check voltage at every connection and that the points are assembled correctly
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Thanks Lobo,
Yes, i am starting to be very frustrated with this.
I have done a coil test and if i check between the primary coils ( blue and black/ white i have the 4.5 ohms as you also state.
When i check the Secondary coils, i have resistance of about 14.28 ohms.
I saw a test on youtube where i had to check for resistance between one primary and one secondary coil lead. ( or probably i got it wrong)
That test said nothing.
I have set the points gap to 3-4 mms.
Not sure if F mark and gap opening match.
I'll check this now.
Thanks for your support.
El__burro
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3-4mm points gap? That seems rather large, should be 15-18thousandths of an inch, cant remember what the foreign metric rubbish setting is, but it's less than 1mm :))
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It should be 0.3 to 0.4mm either missed the 0. Or set them wrong :)
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I guess it's 0.40 on the feeler gauges.
the points start opening just after the F mark on the plate passed the window and it coincides with T being in the window once fully open.
Tried to turn the plate but can't get them fully open with the F in the window.
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Hi,
The old fashioned way is to line up the "F" mark to the pointer and a piece of cig rolling paper should just pull free from between the points!----Ken
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Hi again,
As mentioned... the points gaps should be 0.3 to 0.4 mm. Ka-Ja suggested a good tip to set the (points) opening time. Reading your 'set up' comments.... it just doesn't sound right, ie I wouldn't expect the points to be fully open @ the adjacent T mark, and certainly not expect them to be fully open at the F. (or are you talking opposite F & Ts - ie cylinders 2/3?) Have a good read of the set-up literature, and if in doubt post back... if the points are not set properly it'll explain your starting problem all along...
The coils.... there should be no continuity (connection) between the primary & secondary windings ... they are completely independant of each other. Any continuity here implies a problem.
I said it on the other thread too.... but if your secondary (HT) winding only has a resistance of 14 ohms.... then this it is duff. It should have a reading of abouts 1000x that ... I can't find a specific CB750 value... but generic coils come in at 10-20 KILO ohms. Re-check the reading on your meter, if in deed its 14 ohms I'd start looking for new coil(s)
It has been said before (K2-K6) - ie oil pressure. My suggestion is purely one to see if you can get the bike to fire up. If you do, and assuming you've no oil pressure indicator, run it for only a couple of seconds - don't get carried away revving it up / playing. (Rather stop it, reinstall the original wiring & try again)
Simon
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Here are some pictures of the readings.
Hopefully i just read it the wrong way.
Thanks
Ek__burro
(http://tapatalk.imageshack.com/v2/15/01/19/ae9df2872a9e270539c479b1c970eb86.jpg)(http://tapatalk.imageshack.com/v2/15/01/19/74c450df4fdc4e1ae94b708dab3a7389.jpg)
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Ah! That looks fine... though I say again, I'm not certain of CB 750 coil values... tho they do seem in the right ballpark.
The points. Rotating the crankshaft (only ever) clockwise, set #1/4 breakers to a maximum opening of 0.012 - 0.016 inch, OR 0.3 -0.4mm using your feelers.
Now set the crankshaft to align the F 1:4, and rotate the whole back-plate so that, at this point, those breakers are just beginning to open... using Ken's fag paper trick, borrowed from some school kid if necessary. Its fiddly, and may take a few goes.
Now rotate the crankshaft to F on cylinders 2/3
Now loosen BACKPLATE of points 2/3 and move them until they just begin to open at F mark.
Once done, by default, these too will have the correct t gap of 0.3-0.4 mm as they follow the same cam - ie no need to gap them.
Keep plugging away!
Simon
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Hi,
The fag paper was later superceded with a 12v bulb soldered on two wires with croc. clips (stopped smoking) :D :D :D :D :D :D-----Ken
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Finally a tiny step forward.
I have seen a few very shy sparks at the points. Mainly 1-4.
Still trying to have the points fully open with F 1-4 in the peephole. Can't get there.
Will keep trying.
Thanks
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Hi,
The fag paper was later superceded with a 12v bulb soldered on two wires with croc. clips (stopped smoking) :D :D :D :D :D :D-----Ken
I still use a old indicator holder with two wires but, I kept the bullets on them ;)
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Finally a tiny step forward.
I have seen a few very shy sparks at the points. Mainly 1-4.
Still trying to have the points fully open with F 1-4 in the peephole. Can't get there.
Will keep trying.
Thanks
NO !! the points are JUST opening at F position,
try that
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Hi,
The "spark" is made when the points start to open ie. as soon as there is an air gap when the crank is at the "F" point, yours sounds as though it is well in advance, if the points don't close properly or for long enough, the spark suffers!
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No way, the points open at the T mark.
what if I rotate the plate behind the one with the points on
can I, should I?
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Hi,
Can only go on general set up advice (as per 400/4) set the gaps on the two sets of points to the book settings say 0.3-0.4 mm at maximum lift, line up the 1/4 "F"mark to the pointer, then turning the main backplate, set the 1/4 points to just cracking open using a bulb or even the thinnest feeler gauge you have, lock the backplate, timing should be near enough to run the motor, after that , set up with a strobe----Ken
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Did you remove the points back plate and check the timing advance mechanism behind. Its a set of bob weights that throw out to advance the timing as engine revs build. Sounds like they may be jammed or sticking. Long shot but worth 10 minutes work to make sure. Cheers.
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Check the points cam isn't on backwards (180 out of phase) done that once.
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Some more sparks. Unfortunately I am at the end of the plate. Can't push it more anticlockwise. Still points start opening just after the F mark has passed the peephole. Points fully open when T is in the peephole. Tomorrow I'll remove the plate to check the spark advancer. Yet i don't know what to look for.
Thanks
El__burro
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Mike, what do you mean?
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El Burro, I take it you are using decent condition points, ie, the heel part that contacts the cam aren't worn down/shagged, because you'll never get it right if that's the case, a lot of pattern ones have heels not much harder than chocolate:'(
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Once you take the back plate off (3 screws) you will see the advancer mechanism. Try moving it by hand, the weighted ends should move outwards freely and drop back when you let go. If they dont, free them up with some WD40 and try again.
There is some reason you cannot get the timing on the correct mark. Of course when you find it, it will be obvious. Got to find it first though. Good luck, and try not to get too frustrated. The answer will be right there in front of you somewhere?
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Mike, what do you mean?
The points cam fits over the advance retard mech. The bob weights fit into a slot either side of the cam.
When the engine is revved, the bob weights expand and the lugs on the weights rotate the cam slightly.
It's possible to fit this cam backwards, which leads to a lot of head scratching.
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Take no 1 cylinder tappet covers off.Turn engine and watch the inlet go down and then back up.As it comes to fully closed the F mark for 1-4 the points should just start to open.If not the gap is set to small or advance is 180 out.Same goes for 2-3.
Cheers
Bitsa
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You could try disconecting the wires from the points into the loom and then continuity checking each one down to earth while you rotate the crank to see if they are actually switching on and off as they should do (points closed=connected to earth, points open=contunuity interupted) if they don't then it's possible one of the insulation washers where the wire connects to the points is missing and leaving the wire connected to earth all the time.
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... some good tips coming through.. some background reading that I've found below.
http://forums.sohc4.net/index.php?topic=73769.0
http://www.hondachopper.com/garage/carb_info/timing/Static_and_Strobe_Timing.pdf
K2-K6 mentioned those insulation washers... pictured clearly below.
hairygit's (worn heel suggestion) .... points are cheap... tho' often too cheap, so replace with good quality ones..... cue... Bitsa!
Furthermore... is the whole backplate assembly OEM / quality ... as suggested in the above forum thread... maybe this is your problem... eg adjustment slots incorrectly placed.
IF you don't have fag paper, Ka-Ja & K2-K6 suggest use your multimeter to confirm exact points opening time... see red carpet pic below ... & connect one end to the Blue lead (cylinders 1/4) and the second to earth (ie the back plate), and as the mark sweeps (clockwise) past the F that point should open & the meter's needle fall away as the circuit goes 'open'. Later repeat for the Yellow (2/3 cylinders) and earth. (set your meter to the same scale as you did testing the primary (4.4 ohm) coil winding... and disconnect the points Blue / Yellows from the coils for this set-up routine)
The advance retard...since you seem a bit vague on this assume you've never had it apart... and also that you've never seen the bike running? (if you have seen it running I'd leave it be ...., if not possibly the answer). However, pic attached - bottom pic nicely shows the cam (which freely rotates about its centre spindle) .... which might have been put on upside down! If so, you'll have to remove the springs, remove the two circlips, then the 2 flyweights & finally the cam before replacing it 'the right side up'. Fiddely...
Finally, if it's your intention to strip / restore the bike.... is this all worth it?
Your weekend shaping up nicely....
Simon
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Keep it simple guys. He says he cannot get the points to open on the correct mark, but has seen some sparks at the plugs. That's mechanical surely. Weak spark as the points are only just opening. Knackered points, stuck advancer, points cam on wrongly (not sure how that works though as its pegged), points gap wrong. The problem is around the points plate somewhere. Cheers all.
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I'll concentrate my efforts on the advancer, yet the all area where the points plate seat and also some of the plate is a bit damaged. No big deal though as all the bits are there.
I've attached a picture of the points, the plate and the housing.
I have also removed the advancer and seems fine. How do I remove the bolt that holds it?
Also how do I check if the part mentioned above is fitted 180 degree out?
Thank you all very much for your suggestions
(http://tapatalk.imageshack.com/v2/15/01/21/511e4abc8c29675bd75ebf0f5817a4eb.jpg)
(http://tapatalk.imageshack.com/v2/15/01/21/e7737d6a1a0444e20bc34ec4f60a8912.jpg)
(http://tapatalk.imageshack.com/v2/15/01/21/14767edf2b25b0fcef100a66b595c418.jpg)
El__burro
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Hi,
I think you need help from some-one with good mechanical knowledge, the"bolt" that holds the advance/retard looks to have the head sheared off, is it seized in the crankshaft?----Ken
PS see if the unit will pull off the crankshaft and take another picture!
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Thanks, the tread is fine, how do i take it out, just pull?
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the small center bolt is threaded,suggest you undo carefully with mole grips,if it is tight use plenty of penetrating fluid
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Hi,
The unit should pull off the crankshaft, it sits on the end of the crankshaft on a locating peg, the "bolt" sticking out the middle should screw out, but it is minus its head for some reason!---Ken
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Not sure if i am going crazy but..
In the picture below there is my advancer against a picture of the one Lobo send me.
The mark on it (highlighted in red) is pointing to F2.3 on mine and to F1.4 in his.
Does this matter? (http://tapatalk.imageshack.com/v2/15/01/21/232412cee2e751685097282f117d9ad0.jpg)
Thanks
El__burro
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It looks to me from the "points picture" that the wire from the condenser is touching the base bracket of the points, this would earth the coils and prevent any firing at all.
The circuit path from the both the coil wire and the condenser have to pass into the small securing bolt and then on to the spring leading down to the points contact area and must be insulated from touching anything else along the way if they earth out on any other part then the current is not there to be switched by the points irrespective of any mechanical setup.
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Hi,
The unit should pull off the crankshaft, it sits on the end of the crankshaft on a locating peg, the "bolt" sticking out the middle should screw out, but it is minus its head for some reason!---Ken
No, on the 750's it is a threaded stud, with an m6 nut and the large rectangular headed washer thing that secures the advance/retard mechanism, the smaller fours use a bolt. The stud is screwed into the end of the crank, but there is no reason to remove it at the moment:))
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It looks to me from the "points picture" that the wire from the condenser is touching the base bracket of the points, this would earth the coils and prevent any firing at all.
Fair point, i guess this may explain the arching on 2.3 to the points supporting metal.
Can you tell me anything about the mark on the advancer mechanism?
(See picture above).
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Yes agree with k2 k6 and Hairygit looks like a fibre washer is missing.The unit should pull off and also the unit has 333 on it the 750 should be 300
Love PO planks.
Cheers
Bitsa
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I just went to look at a known good 750 K6 ignition set and the points cam is unmarked (that notch stamped into your one has probably been put there by a previous owner and may not match anything on another bike).
If you look at the advance and retard mech from the front, then te cam lobe that opens the points should point to 2/3 makings and have the base circle next to 1/4 marks. as far as I can see from your pics yours looks te same as mine.
Going back to the wiring, the lead comimg down to the points from the coils has to have no contact with earth at all until it hits the contact face on the points, points closed keeps it earthed, points start to open the earth is interrupted and the coils then fire HT down the plug leads. Any tracking to earth before it gets to the points face leaves the coils switched off.......nothing..........happens!
I'd reasemble the system and set the points gap then make sure you are getting the points to switch on and off as they should be by disconnecting the leads to the coils and continuity testing while turning the crank to establish if you have got them installed properly befor you can move on.
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Hi all. First thing he needs to do is get the points to open at the correct marks etc. Once that's achieved then move on. No point doing anything whilst the timing cant be set. He's probably getting too much info now and getting frustrated. One thing at a time is the best approach, then move on to the next.
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Part number 30220-333-004 is a CB400/4 one
30220-323-005 CB500/4
30220-300-005 CB750 k2
If they are all the same why have different part numbers?I do not know whats the difference but if you fit the right one that's one less thing to worry about. ;)
Cheers
Bitsa
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I was going to ask you bitsa what the 333 comes from but you've already got there. I would take a guess that the 400/4 would need a different advance curve from the 750 so the weights/springs/total advance would have a different spec.
Physically they look compatible and should not stop it running as far as i can see from the pics, you'd have to go with changeing it back to std issue during a rebuild though.
Royhall, I'd argue the oppossite i.e that without a functioning system there's no point in even bothering with getting correct timing as you can't really check it accurately if you have no switching.
My last post seems to have a specifically yorkshire dependent missing H in the te, is there such a thing as a yorkshire typo? ;)
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The plate is correct its for a k2, still, after having ensured that the wires only touch the little screw to the points and nothing else i still am struggling to get the points to fully open at the F mark.
I have a spark on 1.4 sometimes but nothing to get exited about.
In this post the guy has my same issue ( thanks Lobo)
http://forums.sohc4.net/index.php?topic=73769.0
Unfortunately he doesn't mention if/how he's sorted it.
Maybe he never did.
Thanks
El__burro
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All of those on that thread seem to be running though so it shouldn't stop the engine firing and at least running even if it's rough.
You say you've got sparking, is that the plugs or at the points? the points aren't supposed to spark but you may see some.
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.... If the capacitor is faulty
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Thr points should NOT be fully open on the F mark but just opening
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Thr points should NOT be fully open on the F mark but just opening
So it's normal that they start to open at the F mark and fully open by T????????
In the tests I have seen there are sparks at the points too.
The condensers are both fine.
I am lost now?
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Ah it seems easy to do this when it's in front of you but just as easy to miss bits when describing it.
As Bryan says the points start to open at the F mark......but you check the points gap with the heel of the points touching the peak of the cam lobe so this would be the maximum the points would open......that seems to be the point at which someone has wacked a mark into the cam i.e. the point at which the cam should contact the points heel when you adjuct the gap.
The coil will start to fire the plug as soon as the points start to seperate right at the beggining of their movement.
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Okay, that's achievable.
Also as Bitsa pointed out, it looks like the advancer is from a cb400/4. Would it make a difference?
Thanks
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Hi El_burro,... and sorry fellas... just seen two more posts since I started penning this... but I'll be darned if I delete it!!!
Forget the 'T' mark, its irrelevant in terms of what you're trying to achieve... it's simply an indicator that the associated pistons are at TDC (top dead centre).
What you're only concerned with is the 'F' (firing) mark, as the spark actually fires here at idle, ie a few degrees before TDC.
So, and IMPORTANT!!! as the F mark sweeps clockwise past the index mark, AT THIS PRECISE point the associated points begin to OPEN... ie, if you have that fag paper gripped in them... it will release here.
To recap then...
(1) ignoring all markings / indexes, just rotate the crankshaft to whatever position opens the 1/4 point widest. Now via the 1/4 POINTS individual backplate, adjust this gap to 0.012-0.016 ".... OR 0.3-0.4mm
(2) Now you can turn the crankshaft clockwise to align the index & F 1:4.....
(3) Now rotate the whole points backplate (3 screws need loosening) .... fiddling it forward & backwards to just get that sweet spot where it releases the fag paper at the F 1:4
(If you can't achieve this rotational position there is something fundamentally wrong.)
(4) Rotate the crankshaft clockwise, ... and double check the fag paper releases precisely as the F 1:4 sweeps past the index mark.
If not repeat from step 2 above.
(5) Rotate the crankshaft to any position that opens breakers 2:3 to their widest position, and set these to 0.012-0.016" etc
(6) Rotate the crankshaft to align the F 2:3 index, and now move the MINI backplate of those points so that they JUST RELEASE the fag paper here.... fiddley.. will take a few goes to get it right.
(7) Rotate the crankshaft clockwise, ... and double check the fag paper releases precisely as the F 2:3 sweeps past the index mark.
I apologise to be repeating, but you do seem a little confused as to their sequence. Can I suggest you do use (eg) fag paper.... for now it's a whole lot simpler than extra wires.... and will be fine in terms of just getting the engine to run.
Oh, and yup, whilst messing with the points you would expect to see the odd spark between them...
Simon
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I may be wrong but I can't see the 400 mech stopping you from running the engine.....it may have a different state of advance that will affect good running but should be ok to run the motor and check it out......something to correct with the right part later during rebuild I guess.
It looks as though you are steadily getting there as you've been through the coils/feeds/switches etc, there must be a point at which you've eliminated most things.....bit of a crash course in ignition systems really.....and all worth it when it fires.
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FINALLY.
I HAVE SPARKS ON THE PLUGS.
thanks indeed for your support, now what is the next step.
Tomorrow ill put the plugs and try to fire it up.
Hopefully it wont take another week.
Thank you.
El__burro
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Great news. What was the problem?
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A bit of everything.
Mainly i was trying to get the points to be opened at the proper gap af the F mark.
Eventually went back through all your answers and set it right.
Eventually there'll be more questions tomorrow.
Thanks a lot
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Yay, at least you're getting somewhere and nice to get some sparks out of it....well done.
Next step is to make absolutley sure that you have established a good oil supply to the motor/pump/cam etc....has it got the oil light going?
If you are confident it's ok then it would be worth trying it to see if it'll fire.
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Well done you. I felt like shedding a tear for you at times. I have been watching this post with interest, only understanding the very, very basics of it due to my limited knowledge but I have learnt an awful lot, thanks :-* :-*
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Well done for sticking at it persistence pays off. :D
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Thanks, never give up. As long as you all don't give up on me.
Oil light is off but having drained all the oil via the plug in the sump, I better check that properly.
Also I need to find a way to feed the fuel.
Thanks
El__burro
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Fuel feed, i've always used a 150ml syringe outer case stuck down the pipe to the carbs as you can fill the float bowls via this and when it's running you can see the level going down.....use elastic band to hold it vertically on the main frame tube.
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Are we working on hairdryers or something? ;) ;) elastic bands really?
Cheers
Bitsa
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Well done you. I felt like shedding a tear for you at times. I have been watching this post with interest, only understanding the very, very basics of it due to my limited knowledge but I have learnt an awful lot, thanks :-* :-*
Shed a tear? someone get me a bucket ;D ;D ;D
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Well done you. I felt like shedding a tear for you at times. I have been watching this post with interest, only understanding the very, very basics of it due to my limited knowledge but I have learnt an awful lot, thanks :-* :-*
Shed a tear? someone get me a bucket ;D ;D ;D
Oh do shut up Trigger, I would cry for you to ;D ;D ;D I am a sensitive soul and feel others pain and frustration :'( :'( :'( :P :P :P
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Well done you. I felt like shedding a tear for you at times. I have been watching this post with interest, only understanding the very, very basics of it due to my limited knowledge but I have learnt an awful lot, thanks :-* :-*
Shed a tear? someone get me a bucket ;D ;D ;D
Oh do shut up Trigger, I would cry for you to ;D ;D ;D I am a sensitive soul and feel others pain and frustration :'( :'( :'( :P :P :P
I sensitive nurse ? Did not think there was such a thing ;)
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Elastic bands, yep I couldn't think of anything proppa to use ;D not like those things real mechanics have nowadays like a hospital drip to feed petrol in.
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Congrats.... next post from you hopefully.... " It runs!"
Fingers crossed....
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Congrats.... next post from you hopefully.... " It runs!"
Fingers crossed....
I just wish.
After removing the carbs floats I discovered Pompeii.
(http://tapatalk.imageshack.com/v2/15/01/22/36dee09409aab7fa05e167ae450baa69.jpg)
I guess my next step will be carbs cleaning.
First removal.
I am trying to pry it off the engine but I am scared of making a damage.
I have applied some DW40 with no success.
Shall I just cut off the rubbers?
(http://tapatalk.imageshack.com/v2/15/01/22/dcaac861f8fb5370716a1b7948ccf112.jpg)
Thanks
El__burro
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don't cut the rubbers unless you really need to,and check you can get replacements !!
undo the clamps nearest the engine,and wrestle the carbs off,
meanwhile as your doing this,I suggest you leave the bowls to soak,ready to clean,
keep up the progress,it will run !!!
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Warm the rubbers with a hairdryer to make them more resilient. You really don't want to split them. Bear in mind not only are they old but its cold as well
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Hairdryer trick worked great, also i have used one of the clamps to squeeze it in the middle so it would open up the two ends.
(http://tapatalk.imageshack.com/v2/15/01/22/e52ad2e8b6a5977f0ef2b74d90778242.jpg)
Now I need some containers and a lot of patience.
Thanks
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That's a good idea
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Managed to separate the carbs with no major problem. One of the spring loaded screw decided to play tough and I messed it up.
How do I slide/remove the pin that holds the float? (http://tapatalk.imageshack.com/v2/15/01/22/1f64699fa5c501433f027339bf73d84b.jpg)
Thanks
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Having just taken the carbs apart on my 400/4, 3 of the pins came out really easy by grabbing the end with thin nose pliers and pulling/ wiggling gently. The fourth needed a bit of WD40 and a tap with the flat end of very small split pin to get it out. Others on this forum advised me to be very gentle and don't bend the pins, so I couldn't use my big hammer on this occasion
;D ;D ;D
Regards
Julie
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Thanks, mine are very stuck.
I will use a spare pin too.
Cheers
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Try heating the alloy pillar that the pin goes through, alloy expands faster than steel, and should ease its hold on the pin, a hot air paint stripper is ideal for it. ;D
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$#!T
This morning I removed the floats from the carbs. Unfortunately one of them cracked.
I swear I used all the care i could.
This had to happen. (http://tapatalk.imageshack.com/v2/15/01/23/3d37a64247ed572facbc75fb38a2ea87.jpg)
(http://tapatalk.imageshack.com/v2/15/01/23/0785c370fa4dcf4e22de50139c6a9dff.jpg)
Can it be fixed? (Please says yes).
Thanks
El__burro
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The crowd over the pond swear by JB Weld but I have never used it may not like petrol.Alternative start looking for a carb body on the eBay's unless some one on here can help you out with one..
Best of luck
Bitsa
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Thanks Bitsa, I've read a few posts on their forum. It looks like JB Weld is not fuel friendly, so I have to look for a replacement carb.
I have seen a few around but, does it need to be the same #.
Mine is #1, but how can I tell for sure?
Ps anyone out there has a spare one to sell...
Please PM me.
Thanks
El__burro
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Is number one carb the one with the choke lever?I believe it is so unless carb 2 has the same fitting hole its unique so that's how you know whats right
3 and 4 are arse about faced linkage,air screws and drain bowel screws ;)
Cheers
Bitsa
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here is a link to JB weld
wishing you well,
also,if you carefully drill holes in the stem,to locate and add support
http://www.amazon.co.uk/J-B-Weld-Original-Epoxy-Adhesive/dp/B0006O1ICE/ref=cm_cd_ql_qh_dp_t
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After 2 hours research i went on to buy Seal All, its an adhesive/sealant resistant to oil and fuel, it's recommended for use on carbs floats.
Hopefully that'll do.
Also, where is the best place to shop for carbs needles and spares?
Thanks
El__burro
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I can see you're in the sh1t so you can have one I've got spare in the shed. PM me your details and I'll send it.
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Even though its not for me Mike you are a sohc gentleman
Bitsa
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I can see you're in the sh1t so you can have one I've got spare in the shed. PM me your details and I'll send it.
lovely gesture Mike,
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Agreed
Bitsa :D :D
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Sorry to raise your hopes but after seeing the photo you just sent me, I realised we were talking about different bikes. My cards are for a 400.
I've got a right load of omelette on my face now.
Once again, so sorry.
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Don't worry, I'll wait for the glue, if that doesn't work I'll invest in a carb #4.
Still many thanks for trying.
El__burro
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That carb damage is repairable. There is a guy on our sister site who does it. There may be someone who can do it closer to home.
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Don't think you'll get good results with 'Seal All' as it's fundamentally a sealant type of contact adhesive, whereas you're trying to bond a very granular / small surface area 'post'.
Honestly I reckon you'd do far better with John's JB Weld suggestion... it IS fuel resistant and will bulk the material around the 'post' giving you the necessary strength. (& is very well used / respected within the automotive community)
Regarding JB Weld, in the Q & As below appreciate that it should be applied to dry / clean surfaces .... but when cured is fully resistant to fuel. Ie to not apply it to a wet surface.
If you do use Seal All, and it does a great job do let us know... always keen to learn & equally happy to eat my words.
Simon
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Lobo, on Bitsa suggestion I went to ask the US forum, the answer is no, JB weld will not sort the problem.
There's this guy Jim F, he seems to be doing a good job at microwelding it but I reckon the cost will be higher than buying a full set of carbs.
I'll let you know if seal all is any good.
Thanks
El__burro
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Lobo, on Bitsa suggestion I went to ask the US forum, the answer is no, JB weld will not sort the problem.
There's this guy Jim F, he seems to be doing a good job at microwelding it but I reckon the cost will be higher than buying a full set of carbs.
I'll let you know if seal all is any good.
Thanks
El__burro
You should be able to pick up a single carb body from the states for about $20.
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Ask Trig which carb body I sent him and if it's NOT that one you need I still have the other three somewhere. You can have it for the cost of posting if it's any good.
Ash
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Ask Trig which carb body I sent him and if it's NOT that one you need I still have the other three somewhere. You can have it for the cost of posting if it's any good.
Ash
I can't remember now Ash. It was before my brain transplant ;D
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Ash, I will send you a picture of the one i am after. Hopefully you'll see if it matches any of the 3 you have.
Thanks in advance.
El__burro
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http://www.sohc.co.uk/index.php/topic,7250.msg42837.html#msg42837
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Ash,
The one I am after is marked 657A kk
probably not the same
(http://tapatalk.imageshack.com/v2/15/01/24/83adf900fefbd72f85cc34b4588b03d8.jpg)
(http://tapatalk.imageshack.com/v2/15/01/24/7dc6019ca98fb7808014e2d5ed405ccb.jpg)(http://tapatalk.imageshack.com/v2/15/01/24/0e8807488076d0e59ce1d885685c1093.jpg)(http://tapatalk.imageshack.com/v2/15/01/24/4629530a2df0e0631f71b0975f730206.jpg)
Thanks for trying.
El__burro
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Not sure what the differences are. I know there are specific carbs for K0/sandcast and the later F2/K7, with the accelerator pump but the K1->K6 /F1 ones, I thought would have been pretty much the same bodies. Over to the experts ( Trigger / Bryan/ Bitsa etc ??)
I do have a pair of outer bodies for K7/F2 as well somewhere if anyone ever needs them.
http://www.hondachopper.com/garage/carb_specs/carb_specs.html (them good ole Chopper boys once again ..bless 'em :D)
Ash
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Basically the same body's Ash but, for the price of the post it is worth trying to match.
I still have the set of 857A's that i can't find any reference to. I have the set of 064A, 657A and the 857A and can't find what the difference is.
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http://forums.sohc4.net/index.php?topic=99801.0
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Well I found the spare outer carb. but I think it must be the Left one because the air screw is on the opposite side to the one in your picture. However one of the inner ones looks almost identical to yours but the vacuum take off is on the other side, which may be livable with. Trig what do you think?
Will post pics tomorrow as I am away tonight.
Ash
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Okay, thanks.
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Asked the question here about carb differences 064A and 657A
http://forums.sohc4.net/index.php?topic=144577.0
Ash
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Thanks Ash, I will follow that post closely.
I have glued the carb post with Seal All. Although it is an ex-broken carb, it'll do until I find the proper replacement. Yesterday I splashed some £ £ £ on 4 carbs repair kit from David Silver. Hopefully they will be here tomorrow.
Thanks
El__burro(http://tapatalk.imageshack.com/v2/15/01/28/d39abeb371c840fa405f11e1cdebc046.jpg)
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Sorry for delay. Got this back from US site:
Re: Difference 064A and 657A CB750 carbs
657a and 064a bodies are interchangeable. Stamp only denotes which internals were installed at the factory. Unless you get real creative you cant swap positions due to the crossovers and vent tubes.
Report to moderator Logged
Offline HondaMan
Someone took this pic of me before I became a
Really Old Timer ...
******
Re: Difference 064A and 657A CB750 carbs
« Reply #5 on: January 31, 2015, 07:43:29 PM »
Quote
The 657A carbs are not emission-controlled, the 064 versions are. The difference was/is in the taper of the idle air screws, which control the mixture to 2500 RPM, which [at the time] was the upper RPM limit for the EPA tests. In practice, the 7/8 - 1-1/8 turn mixture change of the 657 carbs is about 15% richer/leaner than the 64 series, due to more accurate tolerances in the later carb.
But, they will work fine together: you may find the 64 air screw must be set a bit further out than the other carbs, like 1/16 turn more, to make the plugs all the same color after 500 miles or so.
THIS IS WHAT I HAVE GOT ..PLEASE CHECK IF IT LOOKS SUITABLE AND THEN I WILL US CLEAN IT
Ash
[attachimg=1][attachimg=2][attachimg=3]
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I see no differences.
(http://tapatalk.imageshack.com/v2/15/02/01/381199f6b946645ccff9208b96e7ef61.jpg)
(http://tapatalk.imageshack.com/v2/15/02/01/2bc9ef208c6b120c144683159d4089a4.jpg)(http://tapatalk.imageshack.com/v2/15/02/01/7a5dae4a3ed7b4e7feb6fe9324036f19.jpg)
Thanks
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;) time to start kicking your guts out
keep kicking it over until oil light goes out it should take about two minutes too get oil pressure up
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I'm not sure why oil pressure light doesn't come on. I have removed all the oil from the engine and have half of the tank left. Do you suggest I kickstart it rather than press the starter button?
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it is VERY important to have a working oil pressure light,
the motor needs to be spun either by kicking,or starter before starting,enough to enshure you have oil pressure,
without that,you will ruin all your hard work in less than 60 seconds !!!!
suggest you check the oil switch.wiring and bulb
sort it for safetly
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That's why I like my oil pressure gauge that's the only Yankee mod I agree with.
Mick
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I'm not sure why oil pressure light doesn't come on. I have removed all the oil from the engine and have half of the tank left. Do you suggest I kickstart it rather than press the starter button?
As per 400/4, with the ignition on, try the wire from the oil switch to earth somewhere, it should light the oil lamp, if it does the oil switch is u/s, if it doesn't, there is a wiring fault
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Mick
Yeah got one of those but got pissed off with keep looking down at it.Its ok here to a degree but in the UK dare you look away from the traffic? :o
Cheers
Ralph
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You don't have to look at it all the time the same goes for your speedo and rev counter. ;)
Mick
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Mick point taken but I love gadets never look at Revcounter only the speedo and thats when I see coppers or radars.
Adored the Humber cars dashboard all those years ago loads of dials ;)
Cheers
Ralph
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Back to work. I am trying to make the oil pressure switch come light go off. I have added 3 litres of brand new oil and as johnWebley suggest I am kicking the pedal until the light goes off. How long will it take in normal circumstances. Bear in mind that I drained the old oil already.
Thanks
El__Burro
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Fire some oil under the tappet covers before you turn it over.
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Last time I did mine I was changing the filter as well and I pumped out as much old oil as possible (via the oil ways in the filter housing face) by kicking it over. Under those circumstances it took the proverbial "ages" to build oil pressure on the starter/kick start.
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Back to work. I am trying to make the oil pressure switch come light go off. I have added 3 litres of brand new oil and as johnWebley suggest I am kicking the pedal until the light goes off. How long will it take in normal circumstances. Bear in mind that I drained the old oil already.
Thanks
El__Burro
you are doing great,I suggest you remove the plugs,and as you can kick it over,it seems ok,so now use the starter,
just spin it for about 5 seconds at a time,so the starter doesn't over heat,
good luck !!!
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Yup I go with that
Cheers
Bitsa
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http://youtu.be/KTYXvUgtz-E
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Excellant but was that white or blue smoke?Make sure you watch the oil level
Cheers
Bitsa
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Ooooooh yeah! ;D
After many kicks the oil pressure light went off.
Then the magic happened.
Just wanted to share with you the first time it roared and what a ROAR.
For sure it needs some adjustments to be fully satisfied but my ambition was to start the engine and hear its roar.
Mission accomplished.
Thank you
el__burro
;D
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The smoke was white, i have to say that the carbs are not fitted properly.
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don't worry to much about the smoke,it will be burning spare oil from the re-assembly,and this time of year there will be
lots of condensation /steam as the exhaust cools in the pipes
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Agreed white better than BLUE
Cheers
Bitsa