rebuild or re-use?

[kingbrian]

k so i got a 94 wr 250 and someone "borrowed" my coolant. so basically i destroyed my bike but when i tore it apart i found everything wasnt so bad. the piston melted a bit near the exhaust port and there is a small scratch on the cylinder i can feel it with my finger nail but it doesnt catch my nail.. basically i dont know if i should just try another piston and ring or what i dont even know if i can hone these types of cylinders... any advice?

 

[only_mixed_gas]

if you want to be safe rebiuld if you want to take a small risk reuse

 

[_JOE_]

I've seen a few guys run a bike with a scored cylinder and not have a problem. I would DEFINATELY replace the piston/rings. The cylinder is probly plated so you can't just hone the scratch out. You should have it checked for out-of-round and gasket surface flatness if it was overheated.

 

[kingbrian]

i dont know if it actually ever "overheated" i had kinda been playin with it all day tuning and what not and fire-in it a few minutes at a time but never actually warmed it up.. so i took off down the street and id guess about 3 miles or so it started runnin like a 500, just screamin, or somethin then suddenly slowed down i downshifted and it shut off. i tried to start it and it seemed locked up (not tight). even then the cylinder was barely warm, thats when i decided to check my coolant :bang: so i pushed it home and when i took it apart i found the rings melted by the exhaust port but that was it other than the little scratch right in that area.

 

[jason33]

check it , hone it re check the measurement and re ring it if its still with in specs
hell some of the hone jobs have really deep scratches in there untill the rings seat ,and ware the bore a lil

 

[motometal]

did you happen to have leaned out the jetting (smaller main jet or lowered the needle/raised the clip)? It sounds like either that or you ran out of gas, or the bike quit getting gas somehow. I'm assuming you didn't change the carburetor float setting. I'm sorta grasping at straws here but anyway my point is...if you don't think the piston damage was from overheating, you may want to "undo" your tuning or put it back to stock once you get the motor back together...or the same thing may happen again.