I have taken down my 1988 TRX350D to the piston. I can see why it doesn’t want to run…the rings are shot and the cylinder wall is like glass. I was happy to see that the combustion chamber did not have a lot of nasty carbon buildup. I will be looking for a shop in NE Oklahoma to prep it for the new kit. I wish to order the kit and have it ready for the shop the cuts the cylinder.

My questions:

1.) After some internet searching I have only found the Wiseco 81.5 mm kit with 10.25:1 compression increase (20%!). I do not want to increase my compression and wish to remain with the stock 8.5:1 but just a bigger bore. Can someone help me with a part number for a 81.5 mm (or 82.0 mm) piston kit with stock compression ratio? I can live with a small bump in compression but I don’t want a bump to 10.25:1 to cause other "old" parts of the engines bottom-end to show their age.

2.) If I was unsuccessful in keeping the timing chain in place on the crankshaft and it jumped a tooth without me noticing, is there a easy way to verify the chain position on the crank? I think I am good but prior to torquing everything I wish to be 100%. I read the OEM manual and it doesn’t mention the chain position on the crank, just "don’t let it fall into the crank case". Is it all based on putting the top end together methodically at TDC and the rest should fall in place? I’m a rookie with top-ends…

Thank you for your help in advance.

Regards,
Polymerjohn