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LANEP123

1999 clutch problem

12 posts in this topic

hey guys i have a 1999 ive had for sometime now and still never heard or seen it run. right now i am working on the clutch so i can try to bump start it (im 150ilbs bike is too much to kick repeatedly).

any way the clutch wont engage at all. ive had the whole clutch out and plates were not stuck nor in that bad of shape. the push rod thats suppose to engage the clutch does not push up against the outer plate. WHY IS THIS HAPPENING!! :rant: any help is greatly appreciated.

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Sounds like you may need a manual:

http://www.yamaha-motor.eu/eu/services/owner-manuals/index.aspx

http://www.yamahaownershandbook.com.au/?r=0

Meanwhile, how many pieces is the push rod in? There should be a rod about 5-6" long, and another shorter "rod" that has a release bearing on the end (items 19 and 15 below). The clip #18 holds the bearing and race #16 and 17, on the short rod. If that short rod assembly's not there, that's the trouble. The clucth should have 8 total friction plates alternating with 7 steels, and the outer plate in the stack was originally slightly different from the rest.

Another possibility is that at some point it may also have been converted to a later style 3 piece push rod that uses a steel ball between the long and short rod assemblies. This came in with the 2001 model YZ426. The giveaway is that the small end of the short rod has a socket in it to receive the ball. If the ball's missing, that would cause your troubles too.

51630_clutch.gif

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the bike has both the rods but they just seem about an 8th to a 4th of an inch too short. The swap of the clutches would seem to make sense however the rod is not "grooved" at the end for the ball. i forgot to add that until the very outer plate (#6 in the schematic) is bolted on, (ie hand pushing up against it) the clutch does engage.Then as soon as all bolts/springs are in it doesn't line up.

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i forgot to add that until the very outer plate (#6 in the schematic) is bolted on, (ie hand pushing up against it) the clutch does engage.Then as soon as all bolts/springs are in it doesn't line up.

Not sure I follow that. First, the term "engaged" used in terms of a clutch means that the clutch lever is released and the clutch is "holding". The opposite condition is disengaged, meaning the clutch is released, not holding the engine to the trans shaft. Is that how you are using the term, or do you mean something different?

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with my hand up against part #6 the rods push it out (disengage?) when the lever is pulled in. as soon as all bolts and springs are put in this no longer happens as the rods become too "short".

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So, with the springs in place, does the lever lock up, or does it simply move without doing anything to the pressure plate (#6)? Does the lever have resistance and spring back out when you squeeze and release it?

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with the springs in place the lever moves freely (cable is not hooked up atm so its part #20 thats moving freely) as for springing back out it does but only because of the spring on part #20

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Without being there, I can't make much out of this. What you are saying does not add up logically, unless when the pressure plate is being held by hand there are fewer clutch plates in the stack. If the rod reaches the plate and moves it off the full clutch stack without the springs it should do so with them on, since the pressure plate stays in the same place. But you say the cable isn't connected. Are you sure that it's just not that you can't move the arm by hand? Try it with the cable, or by using a pair of pliers or a Crescent wrench to move it through the full range of its travel.

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i know it doesnt add up and thats why ive been struggling with it so much lol. there are no fewer plates than before. as for being able to move the cluch arm when the plate is bolted up, the arm moves freely then maxes out on rotaion, at the end of the rotation the second rod(#6) sits up against the plate but if you were to move the clutch arm any more the end of the first rod(#19) would come out of its seat on the clutch arm (#20).

could it be that the first rod(#19), where it sits on the clutch arm(#20) has worn down so much that its simply too short?

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another good point. and at this point in time i have no idea what to do.

this bike has been sitting in my garage for close to a year now. I paid 700 for it originally when all it "needed" was a carb clean. after cleaning that ridiculously dirty carb and paying for a new slide and to have some one tune it ($225) i have close to $1000 into this bike and running and in better cosmetic condition than mine they go for 1200ish out here. I will never buy a "project" 4t again.

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