400ex question.

[tbone247912]

i have a 400ex it has has 30 for compression. the cylinder wall has no scratches and looks good. its the stock piston in it. i noticed the first ring it collapsed or just stuck shut the other one isnt. should i just change the rings. or just oem piston and rings and change it or get it bored out 1 time. and go with a je piston kit. also i cant seem to find a good gasket set. i was planning on getting the crf450r timing chain because i keep hearing you can use it and its alot stronger. i was also planning on relaping the valves and posibly changing the valve seals. idk how far i should go into it. help me out

[bliberty21]

Oem gaskets are the way to go. What year is the bike/how many hours are on it? I personally would put a JE high comp kit stock bore if the cylinder isn't in to bad of shape after you hone it out and be done with it. Depending on how much time is on the bike and the extent of the shims you might just want to replace the valves. If I put a new piston in it I am putting new intakes at least. Unless something went wrong with barley any hours on the motor. Hope this helps.