nikasil boring questions

[Quadrcr716]

i have a pc2000 265 powervalve motor with a nikasil cylinder and i think that it needs boring or new nikasil or something this is my first nikasil cylinder i rode it today and i could here what sounded like piston slap and i took the head off and i had quiet a bit of play with the piston in the cylinder so i figured that it needed reboring or redone but i do not know if i can bore it again with nikasil or if i have to have it redone with nikasil again and stat over with the same bore again someone please fill me in on this thinks ryan email me at Quadrcr716@aol.com

[GPracer2500]

Either 1) you can't bore a Nikasil cylinder without replating or 2) special diamond honing tools must be used to take off a tiny layer of coating--not just any shop will be settup to do that.

You can "clean-up" Nikasil with a ball hone (just be careful not to harm the plating at the edges of the ports) or even just clean it up with a scotch brite pad. That is, if the Nikasil coating has not been comprimised. "Cleaning it up" doesn't remove any orignial material, just gets rid of any piston and ring material and/or other junk that has bonded to coating.

Have your cyclinder professionally measured to determine it's condition. If you can visually see scoring that has compromised the coating, you'll need to re-coat.

That's my understanding of Nikasil.

[Quadrcr716]

ok thanks for the info i don't think that it is messed up at all i was just running it and i could here what sounded like piston slap and i took the head off and i can move the piston back and forth whith my finger i will carry it somewhere and check my brother just bought it off ebay so they might have sent the wrong piston thanks for the reply

[Quadrcr716]

does anyone happen to know how much it would costto get my cylinder rebored and plated i miked the cylinder and it came out to be 68.2625 mm and the piston that came with it was a 67.46 LOL i guess when he told us the piston was ran in the cylinder he meant a long time ago LOL but i am not for sure if a 68.2625mm cylinder is too big for a 68mm piston or not if someone knows if this is to much clearance between the piston and the cylinder wall please let me know thanks ryan

[chad502ex]

http://www.mt-llc.com/index_home.shtml

[250rider]

do a ring check first to see maybe if you just need a new ring, take the ring and place it in the cylinder evenly, measure the ring gap. its should be somewhere right around .004