Engine noise

[PEB]

Glen, I found on the 02 I had to float the clutch side bearing to get the crank centered. The 99 i rebuilt i didn't try to center.

The ignition bearing sits all the way in the cases with the outside face of the bearing up against the case. The clutch side bearing sits out a around a half mm from the cases leaving what I presume to be an "adjustment".

When I tightned the clutch end of the crank, the crank would walk through the bearings untill it came up tight to the inner race. I remember the little POP fom when I did the 99 and it did it again on the 02. I tore it down and figured out how much I wanted to move the bearing. I baked the clutch side case just long enough to get it hot, and then with tiny taps of the case on a cookie sheet I got the bearing to wiggle down to where I wanted it. On reassembly when the crank moved a tiny bit it moved to where the clutch side bearing sat and came out almost exact. Had I acccounted for the gasket squishing it would have been closer.

I think alot of vibes come off the clucth. Is there a way to balance it?

[GMP]

Paul,

Good point and makes a lot of sense in your case. On my '00 though, there was distinct axial play in the assembed motor. You could pull/push the crank in and out by the flywheel over 1mm, and hear a clunk as it hit each side. When I tore it down, the bearings were a very tight fit in the cases, it was the crank that was moving. Tolerances I guess. Another way would be to seat the bearing fully, and add a shim(s) between the crank and inner race.

When I rebuilt the '01 XC125 I was able to drift the crank as well. On that motor, the primary pinion is splined to the crank, so I imagine the force of the nut being tightened is not against the bearing inner race, but probably against the spline shoulder. Interesting enough, it had the same problem as my '00 250, loose crank journals. They were slightly blued from heat when torn down. A GG 125 crank is a rare and expensive specimin, so we had it plasma sprayed and remachined.

As far as the clutch vibes, could the dampers be loose? I think mine is perfectly normal and typical, better than a KTM for sure and better than a Husky 250.