Top end Maintenance

[leaper]

Hey all, just took of my head on my cr125 95, head was light brown and on one half it was silverish tiny little dots. ANy idea what it was.

Piston crown is perfect with no dints or scratches and has the even carbon layout on the top of it.

Piston reads B OEM 53.940. ANy idea what piston this is? cause the shop replaces it with that and i had a wiseco in it before. They musta just changed pistons when i did the full rebuild.


What should i do now? chuck in a wiseco? or chuck in new rings. Il get some photos for you guys tonight.

The piston is 53.82mm just above the intake window and 53.94 at the base. The piston pin seems fine, its a tight fit into the piston and when it fits into the top end bearin there is no play. But i think the top end bearin has a slight budge in it very small.

[dhighlan]

Dots or dimples? Sounds like it is good so far. When you were given dia. of piston did you mean cylinder? The bore measurement will be given in the manual. Something like 15 mm from the top of the cylinder. The manual will also give you clearance measurements from bore to piston, you will want to get the corresponding piston to the measurement of the bore. I like to change everything when I am in there but doing just the rings is fine if everything else checks out. I like to error in the side of caution myself (just my weirdness) not always necessary just feel comfortable that way.

[leaper]

it was more like very tiny little dots

[leaper]

ok well i took my stuff to the shop and i found it its a vertex piston.

Dood said piston and bore still in good nic and he gave it a quick hone to get the glaze of and its good. He said just juck in a new ring and it will be fine for a while.

SO i orderd ring and circlips.