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Clutch sprocket shims

Posted: Mon Jul 13, 2009 8:02 pm
by carlos fandango
Ive been trying to line the sprokets up, but the clutch sprocket is to high, by 1mm, with a 0.8mm shim underneath it. :cry:
How is the best way to line this up? would it be ok if i put a shim on top of the dished washer, underneath the crank sprocket?

Re: Clutch sprocket shims

Posted: Mon Jul 13, 2009 8:24 pm
by andylaw7
i have heared of people using 2 dished oil throwers under the front sprocket to achieve the right height .you would have to measure the thickness ?
andy

Re: Clutch sprocket shims

Posted: Mon Jul 13, 2009 8:43 pm
by Diablo
Give MB a ring. I've got different sized thrower washers from them before. From memory(ie check this bit) Spanish ones are thicker and may help.
I have to say though I have had this problem before and it was solved by replacing the front sprocket as when i compared it to others the teeth were in the wrong place. you will get batches like this via India every now and then so it may be worth checking your front sprocket against an old one.

Re: Clutch sprocket shims

Posted: Mon Jul 13, 2009 8:45 pm
by shocky
spanish dish washers are thicker so im told id try several types or measure them first id contact a good tuner and see if they have a solution im sure your not the first person to have this problem

Re: Clutch sprocket shims

Posted: Mon Jul 13, 2009 10:42 pm
by J1MS
Indian case by any chance..?? Could just be a faulty sprocket... But if its not then it could be the Engine case...
If it is I have had a similar problem and the cause on mine was the Indian machining done to the casting.... On a couple of mine the drive bearing seating wasnt machined in deep enough, and as the sprocket sits on the end of the crank & the crank locates on the bearing, this throws it to low down.. I couldnt space it by Clutch shims as "nothing" was thin enough...

What I did....
I used two standard thrower washers that sit under the assembly instead of one, then shimmed the clutch to match.... But the problem is if the crank sits too far to one side, and if its a fixed big end with little or no side float then the rod gets a sideways force exerted onto it.. This is then transfered to the piston and barrel showing up as excessive wear and can cause the crank to fail... I used a crank with side float to get round this and relieved one side of the piston the inside face of the gudgeon pin boss "Mag side" to prevent side thrust... Had the same on one other engine that I built for my mate Pete on his Rapido but bodged as best as I could to get round it... both been fine up to now... Have touched on this subject before but got no response... Thought I would mention it as even if its not the problem with yours.... as I am sure mine cant be the only ones... Or am I just that unlucky..??

Re: Clutch sprocket shims

Posted: Mon Jul 13, 2009 11:34 pm
by carlos fandango
yes its an indian casing, but its an old one (gp150) i did notice the crank sat over to the sprocket side more ( so left gasket off mag housing to compensate).
The crank is an af one with shims, which funnily enough has just twisted :( which is why im checking everything) it is in a rb20 which has the jap piston and the little end floats, so i dont think the two thing are connected
I know about the spanish dished washers, but the reason i asked the question is ,that i tried a 1mm clutch shim and it was a perfect fit over the crank ;). I haven`t heard of anyone trying it before though, and just wondered if it would be ok? i cant think of any reason why not.