classic motorcycle forum
Motorcycle Discussions => British Bikes => Topic started by: slidder on March 06, 2009, 07:42:11 PM
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I tried to search this topic but got no results.
I just bought a used 1968 Tiger. When I try to kick start it the pedal slips as if the clutch is slipping. There is a lot of slack in the clutch cable leaving the clutch lever useless. When I bought the bike the clutch seamed fine, now there is slack and a slipping kicker. Any ideas?
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From what you have said, it sounds as though something has come adrift. You are going to have to take the primary side down to check the clutch out. If the bike has had a recent rebuild, its possible that something has worked loose, maybe the clutch centre nut, or one of the clutch spring screws. The only way to tell is to have a look.
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Yes, this was a recent rebuild done by the previous owner, a professional. When the bike arrived I was able to kick it several times then it started to click. I replaced the ratchet gears and was now able to crank the motor over by hand (I removed the spark plugs) and everything seemed fine. I then replaced the spark plugs and tightened up the cover but this in when I noticed the slack in the clutch cable and the kicker would slip. Could I have done something to cause this? I can still turn the motor over slightly by hand but I get the slip when I use my foot.
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Need more info.
"Slips" as in you can feel the clutch plates slipping, or slips as in no engagement of the kicker?
Cable slack shouldn't matter either way.
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The kicker is working, it feels like the clutch is slipping.
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Has it worked since it's been reassembled?
If not, it implies that either the assembly or subsequent setting-up was wrong.
If it has, then has the primary been over-filled with oil? I had a crankshaft oil seal fail which allowed engine oil to enter the primary. It worked OK at the time, but next time I came to kick it, the clutch was slipping too much to start it.
Worth checking.
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As Rex has asked, have you had the bike running since you,ve owned it, or did it start doing this straight away. If it started straight away you should have taken it back to whoever you bought it from, if, as you say, he is a professional, he should have fixed it for you free of charge. However, since you have done some work yourself, he may not be willing to touch it now.
You say you changed the ratchet gear, why? was it worn or damaged. Whatever, you are going to have to strip it down again to check what you may have done wrong, I take it your using a workshop manual for this. You may have assembled the clutch lever in the gearbox wrongly somehow causing the clutch to be held off.
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The builder started it and ran it through the gears before he put it up for sale. I had it shipped about 800 miles by truck to me. I tried to start it, the motor turned over several times then the clicking started at the ratchet gears. I was able to watch these teeth skip while the cover was off. I replaced the ratchet gears and put everything back together. That is when I noticed that there was now slack in the clutch cable that was not there before. I tried once again to start it but this time instead of clicking the pedal went down as if the clutch was slipping. I took the cover off again and replaced the kicker so I can see what was going on, the ratchet gears are doing fine this time but it is not turning the motor over.
Any ideas?
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the builder of the bike should at least be able to give some advise if your not able to return the bike for him to look at,failing that i would be looking at the primary side,drain oil remove the cover check the clutch springs are adjusted up enough and even,the clutch basket has not come loose on the shaft ie the retaining nut and tab washer have not worked loose,also unlikely unless the bike has been given some welly the woodruff key may have stripped off the keyway.but if the cable has gone loose its probably the springs or the retaining nut
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I am going to forward all this over to the builder before I open up the primary side. He knew about the ratchet gears and sent me replacements but I have not told him about the slipping problem I have now. I was hoping it was a two minute fix that may have been obvious to some Triumph vets but now it seems it my be one of several different things and it should be left for him to tell me what to do next. I will let you guys know how he handles this, he has a good reputation as a British bike restorer and makes some pretty nice bobbers from basketcases. He is located in Atlanta, GA, USA and I am in PA so sending the bike back or having him come here is not my first option :(
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Lets think this through, under normal circumstances with everthing set up as it should be, when the handlebar lever is pulled, the cable pulls the clutch lever in the gearbox onto the clutch pushrod which forces the clutch pressure plate open allowing the clutch to slip and by dis-engaging the engine from the gearbox, allowing the gears to be changed. So, you say you have alot of slack at the handlebar lever/cable, if a ball bearing had been missed from the clutch push rod this would give you the slack, but not the slipping. so it has to be at the clutch operating end or the clutch itself. My guess would be something to do with the clutch operating mechanisim.
What sort of Tiger is it, Cub 90 100 ?
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So, you say you have alot of slack at the handlebar lever/cable, if a ball bearing had been missed from the clutch push rod this would give you the slack, but not the slipping. so it has to be at the clutch operating end or the clutch itself. My guess would be something to do with the clutch operating mechanisim.
Hmm dunno about that.
A slack cable indicates the clutch is fully engaged (ball or not, usually not) so it's hard to think just how the clutch operating mechanism could be assembled wrongly to cause slip, unless the adjusting screw in the centre of the pressure plate was wound in too far, but then how would a (presumably) lock-nutted screw subsequently wind it self in if the poster didn't do it?
They normally loosen off rather than tighten up, but it's something to check, anyway.
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So, you say you have alot of slack at the handlebar lever/cable, if a ball bearing had been missed from the clutch push rod this would give you the slack, but not the slipping. so it has to be at the clutch operating end or the clutch itself. My guess would be something to do with the clutch operating mechanisim.
Hmm dunno about that.
A slack cable indicates the clutch is fully engaged (ball or not, usually not) so it's hard to think just how the clutch operating mechanism could be assembled wrongly to cause slip, unless the adjusting screw in the centre of the pressure plate was wound in too far, but then how would a (presumably) lock-nutted screw subsequently wind it self in if the poster didn't do it?
They normally loosen off rather than tighten up, but it's something to check, anyway.
If you lose a ball or part of the pushrod and the cable is still adjusted for that piece to be present, the cable will appear to have more free travel,but this would not account for the clutch slip. I agree it sounds as if the adjusting screw is too tight, this would also give slack to the cable.
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Hello,up in PA,
I think I had a similar Prob like yours once before.A friend tried to pull the clutch and because the clutch plates stuck together so well
he screwed up his clutch adjuster stuff on the clutch side.The ball and the rod and the little excenter plate were not all in the right place anymore.This was on a old Honda years ago.Your Triumph clutch adjustment might be similar?Is the clutch wire still in the right place in adjuster?
Hope it helps,
huron
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So, you say you have alot of slack at the handlebar lever/cable, if a ball bearing had been missed from the clutch push rod this would give you the slack, but not the slipping. so it has to be at the clutch operating end or the clutch itself. My guess would be something to do with the clutch operating mechanisim.
Hmm dunno about that.
A slack cable indicates the clutch is fully engaged (ball or not, usually not) so it's hard to think just how the clutch operating mechanism could be assembled wrongly to cause slip, unless the adjusting screw in the centre of the pressure plate was wound in too far, but then how would a (presumably) lock-nutted screw subsequently wind it self in if the poster didn't do it?
They normally loosen off rather than tighten up, but it's something to check, anyway.
If you lose a ball or part of the pushrod and the cable is still adjusted for that piece to be present, the cable will appear to have more free travel,but this would not account for the clutch slip. I agree it sounds as if the adjusting screw is too tight, this would not give slack to the cable.But would allow the clutch to slip.
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I got a hold of the builder and he said I should have a look on the primary side and check the nut that is centered between the three springs. I was able to tighten in another 1/4 turn with a hand wrench (and a screw driver to keep the shaft from turning). He was surprised when I told him that, he said use and air impact wrench to make it tighter. With minimum air pressure the nut stripped and came off. It seems that the slipping is on the tapered shaft. When I get some spare time (rare these days) this week I am going to pull the clutch to see if there is any damage to the shaft. He is sending me a replacement nut in the meantime and said he will talk me through the repair over the phone as well as send any parts I need.
About the slack in the clutch cable, I have not figured that one out yet. It was tight and worked fine when I got it but once I replaced the ratchet gears and reassembled things, that is when the cable went limp and left the lever useless.
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I was able to tighten in another 1/4 turn with a hand wrench (and a screw driver to keep the shaft from turning).
Exactly which nut is it that you have stripped?
It sounds as if you could have have stripped the lock nut on the clutch pushrod adjuster?
And you wouldn't do that up with an air tool normally.
To get at the clutch hub nut you would have had to slacken and remove the three clutch spring nuts and also have removed the pressure plate but you have not mentioned doing that?
Could you also verify exactly which model of "68 Tiger" it is? As "68 Tiger" could be either a 350cc Tiger 90, or 500cc Tiger 100 S,R, C or T. (Hunter did ask that already)
Have you got a workshop manual? (and a parts book?)
As I think they would help you a lot.
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About the slack in the clutch cable, I have not figured that one out yet. It was tight and worked fine when I got it but once I replaced the ratchet gears and reassembled things, that is when the cable went limp and left the lever useless.
If it was OK before you replaced the ratchet gear, then you probably did something wrong in that area, so isn't that where you should have started looking for the cause of the problem?
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He was surprised when I told him that, he said use and air impact wrench to make it tighter.
Now that's worrying when a "builder" says things like that.
Surmising it IS the clutch centre nut you're referring to ( that secures the clutch centre on it's taper c/w woodruff key) but a taper doesn't need excessive tightening to hold; it's what tapers do well. The woodruff and nut then hold it in place.
I can't believe he recommended this as a first step. He does appreciate that the woodruff key would have to be missing for the centre to rotate on the shaft, I suppose? :-/
As someone else said, a good manual would help you, I think.
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If the clutch has somehow become jammed at full or partial lift, due to something in the lifter mechanism being installed incorrectly by slidder when he sorted the kickstart ratchet, then that might not only explain the slack cable and lever, but also the clutch could just be slipping as it would be expected to do if it was being held at full or partial lift, so there may be nothing wrong with the taper or woodruff key?
I hope slidder can fill us in with a few more accurate details about exactly what he has done?
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If the bike is a unit 350 or bigger, then the clutch operating mechanisim should be the three ball type. If after re-assembly Slidder got the balls on load,ie opening the clutch, and then screwed the case shut, this would give both cable slack and clutch slip.
As for the clutch adjusting screw and locknut, Slidder this is where you adjust the free play in the clutch cable, so some clearance is needed here. The cable should be adjusted to take up the slack, but operating clearance is set with the adjusting screw in the centre of the clutch pressure plate. You need about 1/8" movement at the handlebar lever.
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[=6E46404B424D4D4A4042230 link=1236368531/15#20 date=1237408934]If the bike is a unit 350 or bigger, then the clutch operating mechanisim should be the three ball type.
No, the earlier ones were of the scroll type, but it's not possible for the three-ball type to rest in the "operated" condition, as the balls work on a ramp, and the natural rest position is therefore "down" ie clutch engaged.
As for the clutch adjusting screw and locknut, Slidder this is where you adjust the free play in the clutch cable,
Err, no again. This adjustment is meant for adjusting the operating clearance of the clutch pushrod. The cable plays no part at this stage.
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I,ll leave this one to you Rex, you seem to have all the answers. :-X
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[=6E46404B424D4D4A4042230 link=1236368531/15#20 date=1237408934]If the bike is a unit 350 or bigger, then the clutch operating mechanisim should be the three ball type.
No, the earlier ones were of the scroll type, but it's not possible for the three-ball type to rest in the "operated" condition, as the balls work on a ramp, and the natural rest position is therefore "down" ie clutch engaged.
Earlier models, did indeed have the quick thread operating mechanism, but as the model in question is from 1968, it should have the ball and ramp which dates back to at least 1964, or earlier?
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I,ll leave this one to you Rex, you seem to have all the answers. :-X
I wish I did, but unfortunately the two points you made were both incorrect. The three-ball mechanism can't rest in the operated position, and the screw and lock-nut adjuster aren't for the cable. Sorry, but that's basic Triumph mechanics. ::)
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I found where the slipping is (this is a 650 Tiger). I removed the pressure plate and clutch plates. I supported the clutch center so that it wold not move while I pushed on the kicker with my foot. The tapered shaft that has the large nut on it is slipping. I tried to make it tighter with my impact wrench but it was already tight. I loosened it up and ran it back down to make sure it was as tight as I could get it but it still slips. How bad is this? I assume I will have to replace the shaft and what else? I still do not have a parts list with a blow up.
How do you think the builder should handle this? (he is about 800 miles away).
1) I offered to send the motor back to him for repairs or
2) Send me the parts and some cash for labor or
3) Have him pay a local mechanic to fix it.
I have not heard back from him yet.
I will let you guys know what he chooses to do.
How expensive of a repair is this?
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The centre is fitted on a taper, and should grip. It also should have a woodruff key in there too, but clearly it hasn't. You need to strip it out to see what's missing or damaged, and worst case is a new centre + mainshaft needed. Sometimes (if the damage insn't too bad) the parts can be lapped together with grinding paste, but if the grooves or damage is excessive, then forget it and get new as it won't hold.
As for your "builder", he sounds clueless...... :(
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i thought it sounded like it was on the primary side from your earlier posts. as rex has suggested you will need to remove the complete clutch off of the shaft there may be no damage to the shaft it could just be the woodruff key was ommited when it was assembled :o under heavy load it will not hold on the taper alone, or it could be the woodruff key has sheared off in the keyway i did suggest this in an earlier post but thought this unlikely if the bike had been proffesionally rebuilt? if it has sheared check the keyway for damage,also if it has the shock absorber clutch fitted find out if the builder replaced the rubbers in it if they are worn out this will put a lot of extra stress on the keyway.i have had the problem on pre unit triumphs more than once over the years and the first indicators are the clutch cable going slack. Steve
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Sorry, but that's basic Triumph mechanics.
Well Rex, I don,t know your past experience with bikes just as you don,t know mine, I think we,ll just have to disagree on somethings, and us arguing is of no help to Slidder.
We now know that either the woodruff key was left out or has sheared, this accounts for the clutch "slip" but not the slack cable.
Where Rex and I do agree is in our belief the the builder of this bike is clueless. I have great fears of what else you may find along the way.
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just another point on the slack cable slidder.the point in my last post about this being an indicator to a stripped keyway or loose retaining nut,this only comes about when the clutch parts company with the taper creating a gap between the pressure plate and clutch pushrod,as you were only able to do the retaining nut a 1/4 turn this seems unlikely, so as LAB has pointed out there may also be a problem with the opperating side of it aswell .
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Take the clutch cable of, first of all. You want to get that out of the equation. If it still slips, you could have a bent clutch pushrod that's holding the pressure plate off (unlikely, but possible). You could have lost compression in the engine somewhere, and that would give the feeling of clutch slip. You could have oil that's too "slippery" in the primary case (have you used an additive?). You could have too much oil (suggest you drain the primary and try it for a while; it won't hurt to run it with oil in the primary for a day or two). You also want to check the clutch operating mechanism inside the gearbox end cover. Ultimately, you'll just have to drain the primary oil, take the primary cover off, and look at what's going on when you kick over the engine. The main thing is that none of these problems are particularly difficult to sort out. You just have to be methodical and work your way through them one by one. If the engine is running okay, you might try putting the bike on the centre stand, running the engine and using the back brake to see if the revs drop when you brake (MAKE SURE YOU KEEP THE REAR WHEEL OFF THE GROUND!!!). Better still, just ride the bike and snatch at the throttle. That will soon tell you what state the clutch is in. You could simply have worn clutch plates, of course.