New noise ??

[Kwackers]

My 1991 KDX 200 has just developed a new noise - it's always had the familiar KDX sound but now when you rev it there is a new noise I notice when the revs die down. At a guess I would say it is a bearing noise but how do I isolate which one ?? The noise is not affected by pulling in the clutch and is there at standstill so I can eliminate gearbox bearings ?? what does that leave - clutch bearing, main bearings what about big and small end ?? help please.

 

[lightsts]

Did you resently change gear box oil and use something differant? I noticed a new primary gear noise when using differant oils.

 

[Kwackers]

No - same oil, about 15-20 running hours since I last changed it.

 

[Brian]

Mine does that too, and it drives me bonkers. I think it's slightly excessive piston slap, but nothing to worry about.

 

[cr25096er]

my cr250 has a strange noise when u let off the throttle. its the springs vibrating on the pipe check to see if thats it.

 

[Kwackers]

Thanks for the replies - I stripped off the barrel (jug ?) and didn't like the noise from the crank bearings. I have now split the cases and the crank bearings are worn out. All I need now is advice on how to reassemble the bearings / crank / cases...........