gear box chatter

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darren112
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hi guys .just totally rebuilt my gear box due to rear hub play and my li150 gear box 16/46 starting to rip the cork on the 1st clutch plt.so ive gone
gp 200 gearbox second hand (couple of chips where the cursor runs)
new 19 tooth front sprocket
new iwis 82 link chain
new bearings
reedspeed 46 rear sprocket
reedspeed spider
reedspeed springs (mbs are about 3mm longer so should have i used them)
new mb cnc machined pressure plt
started up to day alls well did a few runs up and down the road making adjustments as i went .until the engine got warm and when in neutral you can hear a chatter coming from the gearbox end. pull the clutch in and the noise dissapears?.checked the kickstart and all is well there .any thoughts please
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rog60
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Main scooter: Indian GP200
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Sounds like chain too loose. With 19 x 46 I found that needed an 81 link chain.................
NO IT'S NOT A F***IN* MOPED!!!!!!
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leigh
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is it sitting in neutral properly

Leigh
darren112
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thanks for your ideas lads . but i built this with a fine tooth comb .treble checking everythink .im putting it down to a 38 year old gear box . i think a new box would be an idea :)
stokky
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sounds like may be gearbox shim, did you check after changing the gears over ?

Martin
darren112
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yes mate checked that during rebuild 0.15 :) thank u
Matty
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Have you checked how the gearbox sits with the layshaft? I fitted an Italian SX200 gearbox to my Indian case and luckily it was just about spot on with a 2.0mm shim:

Image

Worth checking with the pics in Sticky's manual. While I was taking these pics I noticed an endplate stud that was less than satisfactory so will change that too. Check everything is my advice, but it sounds like you might have done that already.
darren112
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[quote="Matty"]Have you checked how the gearbox sits with the layshaft? I fitted an Italian SX200 gearbox to my Indian case and luckily it was just about spot on with a 2.0mm shim:



all checked mate gears sit above lay shaft .hard facing on gears and cluster looked perfect .and measured gears all correct.gears turned perfectly with end plt off and on .all i can think off is the chattering is coming from the teeth on the gears and cluster may be worn or a missed match pair .pull the clutch in (breaking the drive gears stop turning )no noise .just weird :)
darren112
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pretty shore now i found the problem .went for a ride on the main road 30-40 mph .do a leisurely change down from 4th to 3rd and the gears wont mesh.do a quick one and they mesh .give it the gun in first and there is defintley a ting ting coming from the gear box .so stripping down when i can . change the gearbox and check all components. :D
Knowledge
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The symptoms you describe in your first post sound exactly like the kick-starter plunger has partially deployed. In other words, the plunger is not sitting in the kick-start shaft as it should (when not in use) and the tips of the two teeth are rubbing on the corresponding teeth on the first gear. All cogs in the gearbox are rotating when the engine is running, whether in gear or out. However, when you pull the clutch in, the gearbox stops rotating and the noise stops.

You will find that the cam that operates the plunger needs adjusting. How you do this depends on your set up. The easiest one to fettle is the "hook" inside the chain case. The harder one is the ramp on the gearbox end-plate.

I think you'll find that this will solve the problem.
Martin
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