- Aug 21, 2003
I just rebuilt my son's kx65 top end, it had about 145lbs of comp. before the rebuild. After having him ride about 20 minutes of easy laps around the yard I checked the compression, its only getting 120 lbs. It starts and runs fine, I'm wondering if this is normal until the engine is fully broke in. If not where did I go wrong, and what do I do from here? He is supposed to race tomorrow, but I'm scared to let him. Please, some advice, thanks.