I recently bought my -04 WR250. It has 12000km on the clock, and the previous owner never did a piston change. He claims he has taken good care of the bike with frequent oil and air filter replacement. He also claimed it wasn't driven very hard.
I took the whole engine out of the bike, to be able to clean everything properly, and to bring the engine inside my house. So here it is on the table:
This is what I have done so far:
Top off:
Cylinder looks fine to me. I can't feel any wear inside the cylinder wall.
Also removed the left Power Valve-cover and 3 of the 4 cylinder nuts.
Now for my questions:
Does it normally get this "messy" behind the PV-covers?
The last nut is inside the PV housing. What shall I remove to gain access to the last nut? The circlip and the axle below? Anyone have any tips for me?
Thanks,
"First-time-changing-piston-on-a-2-stroke-since-moped-age-Harald"
I took the whole engine out of the bike, to be able to clean everything properly, and to bring the engine inside my house. So here it is on the table:


This is what I have done so far:
Top off:

Cylinder looks fine to me. I can't feel any wear inside the cylinder wall.


Also removed the left Power Valve-cover and 3 of the 4 cylinder nuts.

Now for my questions:
Does it normally get this "messy" behind the PV-covers?
The last nut is inside the PV housing. What shall I remove to gain access to the last nut? The circlip and the axle below? Anyone have any tips for me?
Thanks,
"First-time-changing-piston-on-a-2-stroke-since-moped-age-Harald"