Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: stevie on April 09, 2012, 09:59:06 AM
-
Hello all, can someone please give me some advice about a problem with my 400 four that I am restoring? On tick over there is a knocking noise coming from the bottom end (quite bad). This goes off when the revs are raised. It is the same when hot or cold. I have split the engine and all of the shells look ok and there seems to be no play on the conrods. The crank journal shells also have very little rub marks. Any ideas? Some one suggested that it may just be the carbs that needed balancing. Also can someone tell me how if or how you check the primary chain needs replacing?
Thanks
Steve
-
It certainly sounds like carbs needing balancing. It is not to difficult to do yourself if you have or can beg/borrow a set of vacuum gauges, but before attempting to balance carbs you must ensure that the engine is in a good state of tune generally (points gap/ignition timing, valve clearances, engine oil condition/level and air filter. If you don't feel confident enough to give it a go yourself, try to find an independant motorcycle shop to give you a fixed price for doing it, it shouldn't be too extortionate ;D
-
If it knocks at tickover and goes off if revs are lifted, try pulling in the clutch lever, the noise should reduce the same-ish. Its clutch rattle and pretty normal on Hondas of this era. It is made much worse when carbs are out of balance so do as HG says. ;)
-
Are you sure it's running on all 4 at tickover? start it without choke if poss and run for about 30sec, switch off and check if all the exhaust header pipes are getting hot.
If one is cold it cold be a slow speed carb jet blocked and preventing one cylinder from firing properly at low revs which starts as you lift onto more main running jets, can give a quite low thuding that sounds as if it's bottom end.
Sounds as if the bearing shells are all intact, are the gudgeon pins also ok (it's unlikely these are worn but just possible)
As the other posts say, just a general checkover of ignition etc may turn up something.
-
Hello everyone thanks for the replies. Checked it is running on all 4 and it was. Also tried the clutch and the knocking continued. Am going to start the rebuild in the next couple of days. I am replacing all parts that are worn as I go. I will check and set up carbs and see what happens.
-
Did you check the bearing shell clearances with Plastigauge (gage) when you had the engine down to check the clearance against the Honda spec? A couple of my shells on the 750 looked great but they were down below tolerance.
-
Stevie,
What was the outcome of this? I have a very similar problem on my newly rebuilt engine.
Cheers
Steve
-
I would put money on this being carbs out of balance. I had exactly the same problem also. The first time I tried balancing the carbs using vacuum gauges I got nowhere.
I cured this by removing the carbs and setting the carb slides as best I could by eye, then refit carbs and make fine adjustments with the gauges. Result - knocking gone and fears of bearing/primary chain problems allayed.
Search this on You Tube "cb400 4 carb synchronisation"
Dan
-
My newly rebuilt engine too has this knocking in its boots; and I'm at a loss at to whether its 'normal' or otherwise. It was professionally rebuilt, inc new can chain, tho' not primary... which I'm told is fine. I've balanced the carbs pretty bloody spot on (I think!)... the only query here is they pull only 16"Hg @ idle versus the typical book figure of 20-24". Comments on this? (My '72 750 same & runs fine)
The knocking is a little alarming @ 900rpm which is rather slow I guess, by 1200rpm the knocking is 'ok', and by 1400rpm the motor's just silky smooth. Due bike not registered unable to give it a true shake-down, but don't imagine this knocking will mysteriously disappear.
Would really appreciate a definitive answer, its had new clutch basket & springs.
Not truly alarming... Its just that the rest of the bike is so good!
-
Well I'm pretty sure in my case it is carb related as carb 2 still doesn't seem to be working. Looking as old posts this seems to be a common problem on new rebuilds. If I raise the idle above 2k it souns OK but very little throttle response. Below 2k it sounds like the engine is about to break in half.
Spark plug, cap, lead, coil all tested OK. Compression fine. So I've stripped the bottom end of the carbs again, cleaned jets and passages with Wynns carb cleaner and blown through with compressed air. Re-installed but no change at all :'(. Tonight I'll try replacing the pilot fuel jet, fuel valve and float and cleaning again.
-
Post a video and let us hear it, you will find out if it's normal or not.
-
Lynx,
Cant remember if the air screw has a hole through it at the bottom like my 750s.If blocked can give this problem with the slow running side.
Cheers
Bitsa
-
It does sound as if there may be some missing (cylinder not firing) in some of these cases......imagine if you missed firing on one cylinder for one beat and then it got it the next time, then that can sometimes sound like a dull thud.
A question for all cases would be, are the noises a regular beat or sporadic?
A suggestion is to try running it with a good car battery jumped onto it to make sure there is sufficient voltage supply for the ignition system to supply at very low revs.......connecting and disconnecting while it's running will give you a pointer if it has any effect.
Also run it in the dark to see if you have any visible escaping HT supply tracking to earth anywhere.
-
In my bike's case the 'knocking' is constant... and due new battery, new loom / wiring / connectors, new HT coils, new HT Leads, new plug caps / plugs ... new everything I'm not 'thinking' electrics / ignition. Besides, it'll idle fairly happily / smoothly @ 900rpm - tho' I will indeed take a look in the dark!
Due non-availability I've not renewed the cam-chain tensioner springs, and indeed, only adjusted the cam chain by the book.... ie not the screw driver down the hole method which is perhaps the next stop.
Primary shaft bearings new, all other bearings given a clean bill of health...
If the retensioning of the cam chain (via alternative method) doesn't do the trick I'll likely leave it as in all truth not 'bad' - ie I'm possibly expecting too much of 1970s technology.
Finally - just how would a slack primary chain / worn cush's manifest themselves... deep knocking, rattling... ??? (although again, given a clean bill of health)
-
After the third carb strip and clean, things do seem to be getting better. I could balance the carbs easy enough this time and have a ready of 20 cm mercury. Lat time I just could not get them all the same and the were roughly at 16 cm mercury. I also set the ignition timing with the strobe and set the mixtire using a Colourtune plug (pilot air screw now out 2 1/2 turns).
Now it will idle fine at 1800rpm. No knock and good throttle response. Still if I drop the revs to an indicated 1200 rpm it'll knock badly. But it sounds to me like it douing about 500 revs! I wonder if the tacho is reading fast. I tried 2 other tachos. One read the same as the one on the bike and one read 1000 rpm when the one on the bike read about 1250, but I don't know which is right.
Anyway I think the bike will be quite ridable now but I still need to build the front brake calliper and put the gear change on.
I did make an MP4 of the bike running but it's too big to upload to here.
-
Upload your pics/videos to somewhere like photobucket.com and share the links.
-
Cheers Lester...
Gawd, uploading pics enough of a palaver for me..., when I next get to my bike (late Sept), and assuming the alternative cam-tensioning method doesn't 'silence it'... then maybe the audio link will be the way to go.
Cheers,
Simon
-
If it works it's here:-
http://s990.photobucket.com/user/Su_Lincoln/media/1200knock_zpscdaae29b.mp4.html
Steve
-
Cheers Steve,
Tho' not as bad I think this is it! I've not actually felt the exhausts early on after start, ie by the time I have done this the bike has been revved & all too hot to linger & assess. Home again mid month & will investigate further.
Make sure you post 'the fix'. Were your cabs rebuilt with pattern of OEM parts / needles?
Simon
-
Hi Simon,
The metal work all seemed good. I fitted new viton O-rings throughout. I made some new felt rings for the slide pivots. Everything else is original except I have new swapped the fuel valve, pilot fuel jet and float from spare carbs onto the pot 2 carb.
I think I'll throw on my spare carbs just to see what happens. I can't help thinking the is a small fuel or air passage in the carb somewhere that is still blocked with crud, even though everything seems to blow through OK with an aerosol of carb cleaner. They haven't be ultrasonically cleaner. Perhaps that is going to be the way to go.
-
Steve, just a point; in the vid the initial revs are at 1400 rpm not 1200 :)
-
I would try a fresh plug in that pot that's running cold that will make a difference when all 4 pots are running together, cheers ;) Mick.
-
Thanks for pointing that out Mick :-[.
It's not the plugs. I swapped 2 plugs but the same cylinder was cold.
-
No way was that bike revving at 1400. Something wrong with that tacho.
-
Lynx
Sorry to state the obvious but until you get that cylinder running right you aint gonna get that knock to go.Shes dragging a dead piston.Can only be 2 things no compression or no fuel to it.
It really sounds like the carb to me.
Cheers
Bitsa
-
Thanks Bitsa. I think you're right, especially as the knock goes at higher revs when all cylinders are running. So where in the carb do I find this fault/blockage?
-
Probably in your idle & slow running circuits you may have to give your carbs more than 1 good clean to shift the stubborn dirt etc , ultrasonic is probably your best bet but if you haven't got that then carb cleaner and a a compressor for blowing through usually helps ;) cheers Mick.
-
Interesting..... been reading everything I can find about mysteries of 400/4 carbs ...here and elsewhere !!
Listened to that engine knock... heard that before !
My completely rebuilt engine (and carbs etc) does a similar-ish thing from cold.
After learning that the ethanol in petrol is a problem for our carbs and seals, I try to remember to run the bowls empty after a run. But if I don't....!!
...then after a day or two without running it will start only after lots of cranking, but No2 will not fire. Always No2 !!
I usually have to drain a bit of fuel from that bowl and then after a couple more attempts it starts on choke after a bit of coaxing. Bowl isn't full??
After a brief warm up it will idle at 1200 rpm but only with the air screws set just one and a quarter turns out. Any more and it knocks and the idle speed drops could this be related to the float levels which I adjusted to stop the plugs sooting up.
On the road the engine now pulls well , especially above 5K if asked, so the fuel supply is good. Only done 900 miles since the complete rebuild and it's been a tale of shortish rides and carbs-off for work.
Exhaust is standard OE (apart from the two pattern headers DSS supplied) as is the airbox etc.
I think the exhaust note is louder than I remember with my 1978 F"2" (yellow .. reg WGM508T) - but that may be a symptom of this particular engine's state of tune - or just my memory of how quiet and civilised they were?.
Work on the carburettors....
Stripped for re-plating and inspection.
Were u-sonically cleaned individually (I bought a small cleaner from Maplin) and lots of compressed air to clear. Fitted NOS floats, new OE needles, needle jets (tube), all new O rings. The floats were set using the clear tube+modified drain plug method (about 23/34mm after many attempts) so fuel all four levels equal and 7mm below joint faces.
Engine wise..
Tappets set to .002", ignition (Dyna-S) also spot on at idle and full advance.
Cam chain tension also OK. Camshaft measured OK when rebuilt.
Re-bored to 1st oversize, new rings, pistons. Re-shelled the mains and big-ends too.
Balanced the carbs to within half a cm Hg according to my old Davida vac gauges.
Each time the carbs have been off (half a dozen?, lost count) the bowls are spotless with no signs of deposits, gunk etc.
No longer overflow either- I junked the Keyster kit items and re-fitted the original float valves after a through clean up and polish.
My thoughts are that maybe some excess air is getting in - could those felt seals be critical or some other item worn or corroded.
The bodies are apparently very sound and all the passages seem clear. I did read that new pilot jets sorted out idling problems on a 500 four, but mine look fine to me.
Nostalgia..
I got 400/4 fettling "experience" from working on my 1978 bike and clocked up 30,000 miles in all from new.
But the most I ever did or needed to do to the carbs was fit new main jets to suit a Yoshimura 4 into 1 (what a noise) and the bike never missed a beat... unless it rained or the points needed setting. Finally had to fit new tensioner blades and a head gasket to stop the infamous oil weep and chain rattle.
-
.... I'm at a loss too, though in my case doubt leaks in the felt washers areas: mine were in poor shape; and having failed to replicate successfully I fitted good quality / tight fitting rubber 'o' rings (which appear to seal nicely) in place of... ie can't believe any leaks possible here now.
Which begs the question why are they used in preference to standard 'o' rings - was it to provide a source of shaft lubrication; or to minimise throttle 'stiction'.... or what?
-
Wow. Thanks for that. I did make my own felt rings. I haven't checked them since installing (such a pain disassembling that complicated lifting mechanism). If one of these is leaking air, will this effect the idle? I might have to go for the O-rings too. Do you have the right size handy Mick?
-
O rings may create more friction or possibly wear too soon unless greased ? .
There was a website describing a full carb strip and rebuild including making those felt rings.... the link was on the now defunct CB400F.btinternet site but might exist on Yahoo groups?
-
O rings may create more friction or possibly wear too soon unless greased ? .
There was a website describing a full carb strip and rebuild including making those felt rings.... the link was on the now defunct CB400F.btinternet site but might exist on Yahoo groups?
Yes I got the instructions off Yahoo Groups.
-
Thanks OddJob, good info.
With the bike on its centre stand, and at low idle, if I were to 'load' the engine... ie put it into gear & apply gentle brake to the rear wheel, should the knocking noise disappear IF it were due to primary chain rattle? (presumably carb imbalance would 'fail' tis particular test)
Lobo.
-
Then there is that set of damper/cush rubbers inside the clutch basket but they are not serviceable (and not available) as the basket is riveted to its gear of course.
These segments of rubber will be as pliable as hard plastic now and zero damping - another source of noise and chatter further along the drivetrain.
New clutch basket if there is too much play but opinions vary. If the rivets are tight I think it's OK.
Heard somewhere on the web that a few Kawasaki enthusiasts have had sets moulded for their Z650s clutch baskets.
If I could find a place to rivet the gear to the basket it would only need a way of making the dampers !
-
Yes the play on the basket gear is due to the damper rubbers being hard and brittle. there will be no play in the rivet.
I do a few damper rubber sets made and have fitted a few. the assembly goes back together using HT M5 screws. the rivet hole is the correct size to just tap to M5.
Kevin
-
Kevin
Can I buy a set please - cannot see them on your website.
What would it cost for these with shipping to the uK?
Cheers
Simon
-
Simon,
Replied to your email. but yes i have a few sets available for sale.
Kevin
-
So....... popped round to Lobo (Simon)'s place on my 400F today to compare engine noises. Arrived at may be 1:45 or so and by that time Simon had already removed the clutch basket, replaced the cover, filled it with oil, started it (quiet as a baby) then put everything back again, refilled with oil ... all in a day's work.
Took my son with me. 120 miles round trip max attempted speed 85mph on the M3. Pulls top gear into the wind on pretty much all inclines bar one..... but I digress
We agreed that Simon's clutch sounds like a bag'o'nails at tick-over. Even in gear with the clutch disengaged and the rear brake on there is noise, whereas mine is quiet like that and just a bit of noise in neutral. Lines of enquiry such as (may be) dodgy pattern clutch plates to follow up. But yes, quite noisy if nothing to worry about.
Everything else about our engines sounds the same - silky rustling 8)
It has to be parakeet yellow dahling!!
-
Yup, generously Tom came over, and there is a 'problem' with my clutch. Until yesterday I'd had nagging doubts as to primary chain, due a muted clattering in the sump area. I pulled out the dipstick - and bingo, the noise ramped up to a dry metallic clatter suggesting not primary chain as that'd be mostly immersed (=muted). And just to verify, I pulled out the clutch basket, rebuilt the casing... engine sillky / turbine like... no rattles from anywhere.
(Just for reference OddJob, rotational play in the primary shaft about 2mm at its gear circumference)
Help / comments then. Back along I wrongly stated I'd got a new clutch basket, actually its simply new (DSS) A & B plates & new springs. No discernible play in the basket when I had it out this am, all solid - using my toned (not) muscles anyways.
Very wary of ebaying a second hand basket as it could be no better than mine.
If its reckoned all due basket cushs - what is actually the SOURCE of the clatter, mine has zero play anywhere that I can ascertain.
Kevin - do you reckon your basket cushs will fix it.... can you contact pm me details if you think you can help? (Inc postage costs)
Cheers,
Simon.
-
Might be that the assembly is imbalanced somehow... Tolerances, etcetc.
That may give rise to another vibration and so more clatter.
Maybe re assemble the plates by turning them all 180 degrees in the basket?
-
I'll have a go at describing the sequencing there with what you've got.
The drive from the crank passes to the clutch, this is essentially another flywheel albeit remote from the crank. A flywheel wants to spin at a consistent rate (the main reason for putting one on a crank) and imparts it's inertia backwards down the primary drive route if there is a change in crank speed.
Bare with me while I try not to confuse myself here!
When the engine is running then for one crank revolution you will get first one cyl firing while it's paired piston is at tdc at no compression, and the other two pistons at the bottom of the stroke....this is then reversed for the other two cyl.....now these small four cylinder engines sound very smooth but at low rpm there is significant crank speed fluctuation when ever one pot fires as it first comes up to compression (only one cylinder doing this at a time remember) the crank slows, followed by acceleration as the ignition fires that cyl.
That speed change comes through the primary drive BUT is opposed by the clutch which is happily spinning consistently as it has no balance issues.
If you think of what happens to the primary chain top run as the crank slows but the clutch keeps spinning it should go slack momentarily....followed by a whack as the crank speeds up faster than the clutch inertia.......it's this, I believe, that the clutch cush drive is supposed to mitigate, i.e. when the chain twangs it's the cush that should allow some give to stop that being a mechanical clunk that you can hear from outside.
So if the cush drive has gone hard and it should have some elasticity when new, then the small shock load it should be absorbing is just not happening.
You can even get a good demonstration of exactly this process if you put most bikes on the centre stand and let the engine idle.....put it in third or fourth gear and watch the final drive chain as it clatters up and down (the rear wheel being a sort of flywheel will replicate the primary drive inertial effects only on a larger scale).
So in principle I'm saying that there is not enough controlled movent in the clutch cush drive and it's most likely that most older examples would be similar.
See what others reckon.
Nigel.
-
Hi Nigel / OddJob,
First up that thrust washer thought is giving me a sleepless night; I didn't take one off, or put one back. Bollocks! In truth I'm thinking it simply remained in place on its shaft whilst I verified the no-basket rattle fix - mainly because I DO remember, on reinstalling the castellated nut only a thread or two (at most) exposed post tightening. Working in a bit of a rush etc!
Nigel... thanks for the explanation - which all makes sense....apart from the 'bag of nails' cacophony - ie a mixture of metallic sounds. Is it simply the components of the basket make-up, all the rings etc rattling individually - there are for sure an 'awful lot' of parts. This all said, I would have thought an engaged clutch (ie lever in normal position) would be tight enough not to allow individual components to rattle.
Have taken a punt on a 2nd hand basket, and by way of a project plan to order a shiny set of those red cushes above.
Cheers for your thoughts / help,
Simon
-
I follow that...
The generator rotor also adds mass to the crankshaft mass to help reduce the speed fluctuations but there still isn't much flywheel effect overall.
The noise may also be worse if the cylinders are not all producing the same shove at idle?
When I had my original bike the knocking noise was less evident when the carbs were balanced and the timing was spot on.
Some bikes are also a lot quieter with the clutch disengaged. This de-couples the gearbox which mean less mass to be sped up and slowed down with each rev of the crank to reduce the noise.
-
Hi Lobo, sent you a PM. seemed to hang up when sending so not sure if it went through?
Kevin
-
Hi Simon, thanks. sent you a PM.
Damper rubber kit, posting today via registered airmail.
Kevin
-
Posting on this forum is sketchy. I think they are sent but you recieve a blank screen.
Search is marvellous though, I wish they would fix the US one.
-
got the same on my little winged honey...she's idling at just over and around 1000 - 1200 ish ...but I won't get too hung up about it - it seems they all do that sort of thing? More or less? Higher idling speed, as you said at around 1800- 2000 ish (might be far too high I think?) and the tractor feeling is gone...so I dunno...My boyfriend used to dispatch ride on several 400/4 in the early eighties around Ireland and says my sound might come from the hyvo chain...comes with age? - who am I to kid here?
...no, and I won't strip the engine-again!
-
Dear Clem2112,
Have you fitted the new rubbers yet?
-
Lynx....
Err ..Not quite ! :-\
I've been waiting for my cylinder head repair so I can put the top end back together.
Since I am still waiting, Now about to take the clutch out and begin surgery on the basket ....
I'll get some pics of the operation on the forum as I go.
-
Lynx, i sent you a PM, not sure if it went through.
Kevin
-
First reply failed.... probably because I tried attaching too many photos.
Anyway the clutch basket rivets are all out now.
They needed some extra persuasion though...
Drilling the flat heads off freed the retainer plate.
Since the other end (or upset) would be gripping the hole, I drilled into that as centrally as I could (punch mark first) with a 3mm drill about 6mm deep. Then 4mm drill to the depth of the deformed end to weaken it a bit more.
The old dampers were a lot better than I imagined. Still flexible but had shrunk slightly. Also some small cracks around the centre slot corners.
The Honda ones have an asymmetric shape with cutouts too - the new ones are symmetrical and full form but should do the job and without the backlash. Pictures will follow.
Next comes the threading ... WD40 is recommended it seems.
The holes are already about 4.2/4.3 diameter (a new 4.2 drill is a slack fit). 4.2 is the spec for M5x0,8.
The depth of thread will be about 14/15mm ... satisfies the 3x bolt dia rule (ish).
Also have to drill out the plate holes to clear the bolts.
to be continued...
-
Yes, the rivet holes are being tapped.
I thought inserts might be needed too..... certainly if I mess up tapping the first hole !
A small tack weld on each bolt edge to the plate might be a belt and braces way... ??
Kevin (ttr400) says to use red Loctite to lock them for good- he has done a few.
Since the bolts (hopefully) never need to come out again this should suffice.
I'll see how the fit of the bolts "feels" ... I know a local place that just helicoiled my cylnder head (again)
-
Is there enough 'material' in each of the 6 'lugs' (?) to drill a size up and helicoil? Must all be getting a bit 'thin' I'd have though.
Very interested in this one Clem (Simon) as my cushs in the post & this task pencilled in for me soon. Keep the good info coming.
Lobo (Simon #2)
-
Is there enough 'material' in each of the 6 'lugs' (?) to drill a size up and helicoil? Must all be getting a bit 'thin' I'd have though.
True, there is only 2 or 3 mm to the lug sides... hence only an M5 not M6 bolt.
-
Helicoils are not required. just tap to M5.
Kevin
-
All six holes tapped very well.
Plenty of WD40 helped to get the chips away.
After a thorough clean up the gear, basket and plate were assembled with the new rubbers.
Used red loctite thread lock on the screw threads and torqued to 6 lb ft.
There is now no rotational slack between the gear and basket.
Before assembling the clutch I dressed the basket slots on the drive faces using a fine file and finished with emery paper. The friction plates thicknesses were checked at 2,6 to 2,7 mm and look fine.
-
Ok - a bit embarrassing I know...
I'm home for a day soon, and will fit my 'new' / renovated clutch basket courtesy of ttr400 (Kevin) & his cushs. Problem is, I don't bloody remember ever seeing the 25mm thrust washer (# 90455-333-010); very likely its always been there, ie simply remaining in place on the main shaft each time I've dismantled the clutch.
So, question.... if it was missing, would it be obvious, because whilst rattly, the current clutch works / feels / adjusts fine.
... and (2) is there anything 'fancy' about this washer... or can I substitute a good similar sized washer?
If anyone has one in their hands can you measure its dimensions please (primarily thickness) & I'll root around my Brunei tool box before next trip home to save time / grief.
Ta,
Simon
-
:o.. Don't miss this item it out as it does a crucial job !
The thrust washer sits behind the clutch assembly and usually stays put because a film of oil will make it stick to the shoulder on the input shaft and its hole diameter fits the shaft.
I had to look for it and convince myself it was there....you'll see slight wear on each side so keep it the same way round if you take it off.
The top hat shaped sleeve in the basket's bore reacts against this washer when the clutch nut is torqued up. The washer is replaceable and cheap too, shafts are always expensive !
It will be a fairly precise ground width and be made in a specific steel grade for doing its job I would think.
Without the washer in situ, the basket would wear against the shaft as the two rotate at different speeds when the clutch disengages. The sleeve and washer provide a bearing for the basket to spin with a very slight end clearance.
Not sure, but the basket may hit something without the washer in place - with the hex head screws used in the kit the clearance will decrease a bit.
btw... No big change in the sound down there on my bike but glad I did the fix anyway. One of the rivets had lost part of it's head !
-
Cheers Clem2112,
I am indeed quietly hoping it is in place... certainly if there's significant thickness to it I'd surely expect a horrible graunching from within on start up. My missus btw takes glee in that she always thinks I have a hand full of parts whenever I've rebuilt something ... but in truth I'm meticulous and I sure haven't thrown any washer away. If it's missing it'll be from long ago, and a lesson to use a parts diagram on any rebuild versus 'put it back the way it came out'!
It is not easily replaceable, hence my question.... the part (& its later part #) are both discontinued and unavailable on all Internet searches (inc DSS). I have though sourced a 2nd hand piece @ £9 (ouch) inc p&p.
Disappointed to hear you still have clutch rattle... having heard Tom400's 400F & its silky idle.... and indeed my own's silky idle when 'basket left off.... I'm hoping for more. Will be really ****ed off if it remains... have spent a lot of effort sourcing this noise & trying to fix it....
Thanks again,
Simon.
-
Further to Clems recoditioning of the clutch drive cushs... my experience.
Drilling off the rivet heads easy and straight away the whole assembly fell to pieces as the original Cush rubbers 'shrivelled'. As Clem commented; they were not symmetrical.... tho' my take on this is simply the forces on these cushs always in the same direction ... ie compressing them from one side only over their 35'ish years causing the miss-shape.
The rivets! By crikey. They did come out... eventually... but with a drift & wallop enough to wake the devil.. (I only managed this by grinding them flush to the 6 bosses ... ie completely eradicating any possible flare in the protruding rivet shank.)
The rivet holes perfect for the M5 tap with no work... and to ensure the thread 100% perfect I tapped from the back (ie inside of the clutch basket) outwards... giving the supplied M5 bolts perfect starting thread versus chewed thread from 'iffy' starting of the hand tap had I tapped from the outside.
The rebuild satisfying... the cushs a tight push fit, absolutely no play now. Bolts tightened beautifully, with RED Loctite of course.
This Saturday fitment - I do hope this bloody rattle has been put to bed!
Thanks Kevin - a great kit.
Simon
-
Yahoo!
Fitted the 'new' clutch last night & knocking / rattle gone; a big result.
Getting worried.... little left to do on the 'bike(s), ..... will the missus tolerate another machine...?
(er, nope)
-
Fantastic news Simon. Persistence pays off. Hopefully it's not (only) age that sees these rubbers off as mine is obviously old but not worn. Great work you've done on your bike.
Meet up when the warm weather returns perhaps.
Tom
-
That is good news. Well done. I've just ordered a kit from Kevin too.
-
Thanks guys,
To be honest has been 'fun' getting to the bottom of this... have learned heaps. Thinking of applying to F1 for next job.. can fully service the clutch in no time! (so MANY bloody practice runs!)
Next year Tom, catch up again,
Thanks for the help,
Simon.
-
I need another set of clutch basket damper rubbers but I can't get a reply from TTR400. Does anyone know if they are available from anywhere else?
-
Hi Guys,
I'm away traveling at the moment on my CB400F. I flew with bike from JHB to New york and rode across the USA and then up to Canada done around 20000KM's so far. flew from Vancouver to Frankfurt toured around Italy for a few weeks. i am now in the UK (Telford, Shropshire). just done a major sercice to the little 400. to get to the point, i had a clunking sound appear around 13000 km's, thought it might be the clutch. clunking was pretty loud at idle but ok when revved up.
Stripped the clutch last week and found the cush rubbers had disintigrated (I don't think the material can withstand extreme hot oil and heat etc).
So a message to all who i have supplied with my damper kits, check after a few thousand km's that they are still ok.
Put my bike through some pretty hard riding and extreme temp going through the Desert in California so they help up quite well considering.
I have a new design workied out, but will only get to it when i get back to SA.
Incase anyone is interested some specs and how parts help up etc.
520 EK brand chain with sprocket specialist sprockes (alloy rear). Excelent chain, only req adjusting after around 5000km's. just replaced the rear sprocket. so 19000km's on the rear, chain and front still good.
Tyres: Avon AM26 90/90 front, 100/90 rear. still in fair condition, rear squared off slightly but front has plenty miles left on it.
Rims: Morad alloy type, due to load spokes required checking as they lost tension on the rear every few thousand km's. front has excessive run out(must have done some damage somewhere) lost the balance weight and slow speed wobble appeared in Canada, just had it balanced again better but need a new rim.
Fuel consumption: averaged so far around 26km's per liter, or 62 or so USA MPG .
Front brake: pads as new, same for rear shoes. but front brake pivot now has some play.
That's it for now.
Going to the Stafford show in October if anyone is around that area.
Kevin (TTR400)
-
Some trip that !.... You mentioned an upcoming trip on your website.... On the African continent I assumed...going for a world record ?
Btw ...What colour were the dampers??
The ones you sent to me were a dark blue material. So far so good.... I hope!
-
That's an amazing trip. You'll have to write a book on it when you get home Kev.
-
Yes they are blue, i did have some red ones but the material was the same.
I plan to come back next year in the summer, to do some more touring around. anyone fancy a ride to Vladivostok?
Kevin
-
Bravo,
I know where to come when I eventually start up my project and find some rattle/knock!
Cheers and enjoy!
D.
-
Just to add a little info that may be of help.
A product called "Rocol RTD" is used in engineering to cut threads with both taps and dies, I think it's the best product i've used for doing this as it allows a particularly smooth thread to be cut by lubricating and keeping the swarf away from the from the cutting area where the tap blades are leading into the metal. As the cut is cleaner you also get less "oversizing" on small threads which is caused by the swarf being forced between the tap and the metal you are cutting so the finished threads will have a better tolerance match to the bolts you are going to use, making a more secure fixing. For those that haven't tapped threads before, the tap should be rotated about 180deg then reversed 90deg followed by another 180deg forward and repeated until the full thread is done. This reversing forces the tap to break off the swarf into smaller parts and avoids the debris getting jammed around the cutting area.
Nigel.