He ticks over fine though. Yet first happened after a mile riding, shortly after the freeze. Last time happened at set off. This winter is first time ive ran with oil warming to carbs disconnected.
Seems a likely culprit then. Icing will vary according to temperature and humidity and it's pretty normal for the engine to tick over ok but give no power.
The problem persists, cannot quite figure it out - insightful directions would be appreciated! I checked clutch - all seems well - no excessive gaps in teeth, bearing wear. I deglazed the plates. I found a tight spot on the chain, and renewed the chain. The rear pads rubbed a little, so with those removed and with bike on a paddock stand, drive engaged, i get the same snatching - simply unrideable. It will stall unless i slip the clutch, when sprockets, chain and wheels all spin ok for as long as I like. So its not the chain or sprockets, I surmise. Bear in mind this pronounced symptom emerged suddenly in this form during a ride, although i had some intermittent slight indications of snatching at times beforehand, and that may have been due to the old chain’s tight spot. Slipping the clutch is a key clue. - You may disregard earlier report of squeal, that was probably front brake squeal. The cush drive has slight wear, but dont see that as the cause. Im going to take check the final drive sprocket next for wear on the splines while i ponder the matter.
If the problem were on the transmission side of he clutch, slipping the clutch wouldn't help. My guess is ignition or fuel. Did you refuel shortly before the problem started?
Not precisely beforehand, no. Had been standing about two weeks whilst i got new pick up coils and sleeving together. I had prevoiusly been right through the carbs and had it running well for fuel and balance settings. I’ll check the spark at plugs - although i had put new in very recently. i should check for a short on ignition. Ill get a video together.
Now you mention carbs, I reckon a prime candidate is carb icing. It depends upon humidity but in the right conditions, an SS will suffer from carb icing on as much as 8 or 9 degrees. If you let the bike idle for a while (so the carbs de ice) and then the power returns, then that’s your problem.
Here's a couple of videos, one with chain attached , one without. I reckon it's mechanical, and suspect the cush drive. Heard a little clunk is normal, but went ahead and removed the wheel for closer examination - the sprocket rocks more obviously with wheel off, and upon examination the pins show wear. Think I'lll go ahead and order replacement pins, probably bushes too, thought the rubbers are OK; however I cant vouch for the inner sleeve, though I suspect they are less prone to wear. Advice on upgrade of pins welcome - e.g. to titanium or whatever, and where to get them.
I wouldn't bother with titanium, pretty expensive. What about a second-hand carrier? I have several if you need one for a reasonable price.
Cheers Desmo. I wondered if pre-used would be worth it - If they not worn towards the limit, then I suppose why not? Bear in mind, I could opt for a set of standard pins for about £50.00 and that might do the job. Please do PM me with an offer if the carrier is nice and tight.
I badly need direction in troubleshooting this problem. I am stumped. Recap of The problem ——————————— I can basically describe it as ‘chain snatch’ . The chain revolves OK with the clutch pulled in partially - i.e at less than full power, when on the stand, and when riding. Otherwise it grinds up somehow causing it to stall. It used to run OK. The problem emerged suddenly when cruising at high speed for a mile from home. However, signs of of that kind of deterioration were there before . I had replaced the pickup coils just prior to that outing. Upon examination I found a tight/bound section on the chain and the cush drive was worn. I’ve Since done the following: ———————————————— - rechecked pick up points timing; good.Bike starts, idles and revs nicely. - checked rear wheel alignment by ,easing the swingers from pinion to centre of axle. - - replaced worn cush drive pins and rubbers. - - checked the seating of the sprocket drive carrier. - checked the side play swing arm - checked the end play gear shaft (at about 0.015 limit it seems. - checked the mounting of rear suspension unit - - inspected gear shaft for bearings by spinning and tugging - OK so far as I can tell. - replaced chain and sprockets plus retain. The problem remains, although less severe due to work carried out. You can see a video of the problem before working on the bike 3 posts above. Carb Balance ———————————— I have heard that unbalanced power output may perhaps contribute to such a phenomenon - on other bikes … i.e unbalanced carbs. I have balanced the carbs with a decent gauge. The reading does seem to be unstable, depending on the idle revs used.. i.e one cylinder may increase ar the expense of the other at higher revs, and vice versa when I compensate with adjustment of pilot. I settled on something between. The bike starts fine on choke. However it needs a little tender care in adjusting the choke before it settles down on warming up. What could you tell me to look for now? Cheers John
It’s interesting that you say that the snatching isn’t present with the clutch partially disengaged, that’s a clue to the problem, have you examined the clutch assembly?.
hi Mark, yes it is telling. I dismantled the clutch plates, examining the friction linings, tabs and slots and splines - all good. The bearings without further dismantling, seemed smooth. I rubbed down lghtly the linings. Have been running semi-synthetic. Considering the clutch as source of the problem, I need to know whether clutch input shaft could somehow cause it, and I think not beyond plates and smoothness of power transfer. I may be wrong though. Although i have inspected clutch plates , i suppose i cant rule them out absolutely. I think perhaps I should keep power transfer foremost in mind. The function pf the new pickup coils is therefore still suspect (as Old Rider has pointed out) - I’ll have to do electrical tests and now I remember, I should do a dynamic timing check first, which I havent done. I had re-checked the (awkward) static setting.
There's a tiny bearing on the clutch push rod. This can disintegrate which can cause the rod to get damaged. I don't think this will be the problem but have you taken the rod out and checked this bearing? Have you watched the clutch side whilst running?
I had taken the push rod out, yes and the bearing was good. I’d like to watch the clutch whilst running, but its a wet clutch (and an opaque cover)... is there a way?
BTw, Id like to ask the opinion of Arquebus on this, but his membership is now gone, and I see he has re-appeared as guest status ‘ghost rider’ - do you know how i can reach him?
Tbh, I really doubt the problem is with the clutch. If you coast with the clutch disengaged or with the box in neutral, does all appear smooth? If yes, that would suggest the problem is with the motor. If no, that would suggest it’s in the drive train.
