Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: billdn on April 24, 2021, 06:07:46 PM
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Probably an old topic and I have used the search engine which helped somewhat but not completely.
Having purchased a new points plate complete I thought this would be easy >:( !
I've tried both methods in the Haynes and Clymer manuals with no success so can anybody please give me a definitive procedure.
The story so far:-
1) Turn 22mm nut until 1-4 points at widest and adjust to 0.35mm (mid point)
2) Same with 2-3
3) Hook up test light to blue wire (points 1-4) and earth on engine turn on ignition and rotate 22mm nut until F mark for 1-4 aligns with static mark -adjust back plate -light comes on but stays on for about 240 degrees then goes out, same happens when doing yellow on 2-3 side.
4) re - Adjust points gap when F mark aligned back to 0.35mm
5) Sort of spark on 1-4 but none on 2-3
6) Coils are new too.
I vaguely recall something or other about not getting something round the wrong way as it throws everything out but can't remember it!
I'm obviously doing something wrong! Yes I know Haynes are good for bonfires! But the Honda shop manual refers to a strobe and the engine running, be nice to get the b####y thing started!
I throw myself at your mercy and ridicule if that suits!
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If you have had the advance/retard unit to pieces, you can reassemble it 180 degrees out.
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#4 is superfluous, skip that and turn plate until light comes on at the F mark.
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First ONLY use the 22mm nut if you have the plugs removed or you will deform the peg and/or shear the bolt holding the auto advance on.
Second new points have a preservative on the surfaces that need cleaning off
Third you should NOT get a spark at the points, only the plugs
Yes it is a barsteward getting both the points gap correct and the timing spot on and thats even when youdo it regularly!!
If you can make the points plate a less "sloppy" fit in the crankcase it will be easier. Apart from that just patience and perseverance
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If you have had the advance/retard unit to pieces, you can reassemble it 180 degrees out.
Cheers, that clears that up , knew I'd read it some where but forgotten the full story - it's not been apart so no problem!
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#4 is superfluous, skip that and turn plate until light comes on at the F mark.
Thought it was making me chase my tail in ever decreasing circles!
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First ONLY use the 22mm nut if you have the plugs removed or you will deform the peg and/or shear the bolt holding the auto advance on.
Second new points have a preservative on the surfaces that need cleaning off
Third you should NOT get a spark at the points, only the plugs
Yes it is a barsteward getting both the points gap correct and the timing spot on and thats even when youdo it regularly!!
If you can make the points plate a less "sloppy" fit in the crankcase it will be easier. Apart from that just patience and perseverance
Thanks Bryan, for some reason I took the plugs out just it because it was easier, dodged a bullet there!
Have cleaned the points with meths, as read that on other posts when I was looking this up.
From this it seems that while the contact breakers and advance/retard work together ultimately - the setting of points gap and setting the "F" mark with the light are in fact separate actions.
I'll persevere , I've patience a plenty- I'm married!
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The trick is get the gap exact then dont undo the plate screws too much but i bet the gap will alter when you rotate plate!!!
Take your time to get both perfect and in the future when servicing you will be able to set the gap by making the bulb light on the f mark as the only thing that actually wears is the fibre heel on the points.
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Make sure you’re not putting the croc clip on the small bolt thread as opposed to the metal on the wire itself - like I did once. ::)
PS the gap makes a big difference to the timing position and I thought my plate was beyond adjustment until I tweaked that a bit.
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The trick is get the gap exact then dont undo the plate screws too much but i bet the gap will alter when you rotate plate!!!
Take your time to get both perfect and in the future when servicing you will be able to set the gap by making the bulb light on the f mark as the only thing that actually wears is the fibre heel on the points.
Well a couple of days pass and I've been diligently trying to little or no avail, apart from a few pops and bangs.
Bryan you mentioned about making sure backing plate seated well, what did you mean? Spacer/washer behind perhaps?
I have noticed that I can get the light to come on the F mark on 1-4 and 2-3 but when tightening screws up on advance/retard plates it goes out sometimes but a careful giggle can get it to stay on. I believe the F mark position is correct as I can hear a click in the respective coil at the same time.
Plug gap set, btw Clymer says 7-8mm not 0.7-0.8mm!!
When it fires I get a bit of blow back through the carbs and out of the air filter box (filter out as I used a small squirt of Easy-Start!) and the throttle grip twitches with some of the backfires.
Should I use full choke or part choke?
Good spark on all plugs too.
This is a fully rebuilt engine from scratch with new rings/pistons/ rebore etc and skimmed head. New points and point plate assembly too.
Would incorrect tappets setting give a problem also.
Any ideas to try for me?
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If you have decent spark it seems you're more or less ok on routine of setting them.
The point earlier about something assembled wrongly, you can assemble the rotating part of the advance and retard mech at 180 degrees out (the cam lobe being in the wrong place) which would put the timing at near bdc!
You can do a quick test for that by swapping the two coil to points wires over with each other to see if it fires. If it goes, then you need ultimately to correct the assembly and swap them back. But try it first to see if you get a response.
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Good point, or take a plug out and compare the piston position with the T mark on the plate.
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Just as an added point, I would NOT let Easy Start anywhere near any of my vehicles. When petrol vapour burns in the cylinder, it does so at a predetermined rate, (the old octane ratings), this is a small part of the reason for ignition taking place a little before TDC. If you use Easy Start, it burns so fast that it is virtually exploding, and could be the reason for your backfire, and feeling the 'kick' through the throttle cable. If ever you've heard an old diesel being started on Easy Start the sharp cracking noise is unbelievable, and knocks hell out of the bottom end. You often see adverts from people selling 'barn find' imported bikes that have stood for years, and they state that they have managed to get the engine running with a bit of Bradex. Thanks, but no thanks. I've just bought an old CL160, the dealer told me that he had not had it running, just turned it over on the kickstart to ascertain that there was compression, that was good enough for me.
On my 400, I still use points ignition. The one big problem I had some while ago was using a "Ready to Fit" fully assembled backplate. There was not enough movement in the adjusting slots to be able to set both points as required, so it became a compromise. This was followed by one of the condensers failing which gave me my 1st ride in an RAC Recovery truck!
I still had the OE backplate, which was re-installed along with new OE components from DSS. Bliss!
Just to show that I still push my luck, I use a cigarette paper to time my ignition! Please keep the replies polite!
Stay Safe. Mick.
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Good point, or take a plug out and compare the piston position with the T mark on the plate.
I think the marks stay the same as pegged to crank position, but just the cam lobe moving as it rotates independent of the other parts.
In effect it looks ok from initial inspection but the cam itself is 180 out from marks.
To swap it you have to swing the counter weights out of the way and swivel the cam then re-establish the weights.
There's some good pictures on here of the units with align check marks but I can't immediately find them.
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Its the fact the plate is a smaller circle than the hole formed by the posts,
On a really bad one i made 3 bent curved shims held by yhe screws that hold the plate and bend round the edge of the plate to remove any play, there are other ways and any that work without damage are OK
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This pic shows one type
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That's the one, the two little white squares reference the lobe position and can be installed either correctly or 180 out, putting all the timing at BBDC rather than BTDC .
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That's the one, the two little white squares reference the lobe position and can be installed either correctly or 180 out, putting all the timing at BBDC rather than BTDC .
Like the thought but my one has it with the mark in the vicinity of 2-3 mark and a new (not OEM) on DS site shows it also on the 2-3 side , possible succinctly different on the 500/4 and 550/4?
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400/4 plate
[attachimg=1]
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That's the one, thanks rules out that possibility👍
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Made me pause for thought there but yes coils are feeding respective plugs from respective coils -phew.
I checked the continuity on coils today and have continuity on primary and secondary coil, but on checking the resistance I get around 3 ohms and 10-11k ohms across the plugs with caps off but up to 16 when I put caps on - I've read somewhere that the lower reading should be in the order of 5'ish , the upper value seems about right. They are resistor caps of 5k ohms BUT i have fitted non - resistor plugs D8EA's
My other 400/4 runs fine so I think I'll do a swap on the coils and see what happens!
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So removed coils and rechecked ohms , (which were from DS but not standard ones - 'cos half the price! ) Ohms for primary coil 3ohms and secondary coil 11k ohms.
removed coils from 400/4 runner and checked them which gave 5 ohms and 15k ohms respectively, fitted to rebuild and although not running as yet, still need to fine tune timing but sounded much more powerful on attempting to start. Unfortunately I bought the coils form DS over 3 years ago so doubt if I can return them :(.
So beware the perils of pattern parts!
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So removed coils and rechecked ohms , (which were from DS but not standard ones - 'cos half the price! ) Ohms for primary coil 3ohms and secondary coil 11k ohms.
removed coils from 400/4 runner and checked them which gave 5 ohms and 15k ohms respectively, fitted to rebuild and although not running as yet, still need to fine tune timing but sounded much more powerful on attempting to start. Unfortunately I bought the coils form DS over 3 years ago so doubt if I can return them :(.
So beware the perils of pattern parts!
The ghost of Bitsa will be pissing himself laughing at the last line of that post! 






Sent from my JNY-LX1 using Tapatalk
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So removed coils and rechecked ohms , (which were from DS but not standard ones - 'cos half the price! ) Ohms for primary coil 3ohms and secondary coil 11k ohms.
removed coils from 400/4 runner and checked them which gave 5 ohms and 15k ohms respectively, fitted to rebuild and although not running as yet, still need to fine tune timing but sounded much more powerful on attempting to start. Unfortunately I bought the coils form DS over 3 years ago so doubt if I can return them :(.
So beware the perils of pattern parts!
Try Ash's coil fix - for the cost of cheap pattern coils - http://info.sohc.co.uk/download/ashs-ignition-coil-fix-2/
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Thanks Phil, been looking for this.