top end advice

[an]

We are fairly new to the race scene, my son is racing a 2002 kx65 and I'm wondering if it's time for a top end rebuild. He started racing late in the 02 season, the bike has very little practice time on it, mostly just race day riding. The specs given on compression are 157, his checks at 140 (wot 10 or twelve kicks on a cold engine). How useful is compression test as far as determining the need for rebuild? What are all of your thoughts?, is it time, and if not at what point would you suggest. Any advice would be appreciated.

 

[bubbaxr]

You may want to ask some guys at the track one day what they get out of that model. One dad/mechanic that parked next to us once told me they got nearly a season on their green machine. I guess that surprised me. This may be apples to oranges but we got 70 hrs of track and hard practice combined on our CR85 this year. Was overdue at that point (kick starter was feeling a little soft) but still running good. When I picked up top end parts my dealer advised that we change the ring only, every 10 races or so, and the piston could stay put quite a bit longer.

 

[DEANSFASTWAY]

Those parts are all pretty cheap Id install them just for peice of mind every couple months or so. Talk to your friends at the track. Good Luck