I bought an 02 TTR-225 and later found out it has a top end knock over about 3000 rpm and smokes pretty bad. I adjusted the valves in an attempt to quiet it down, but the top end knock continued. When I took it apart, I found .013 piston wall clearance and the oil ring had no spring to it. That explains the smoke, but not the knock. I grabbed hold of the rod and tried to feel if there was any slop in the lower rod bearing. It had a lot of side play, but it was tight up and down. I have a few questions:
Is it normal to have side play at the lower rod bearing?
Could piston slap be causing the knocking noise?
If so, would a rebore and new piston fix it?
Does anyone know what the piston clearance should be?
Head bolt torque?
Correct valve clearance?
Thanks in advance for any expert advice.