Just rebuild my 175 Jackpiner How long should I run the motor before I go racing: Installed new sleeve and piston had clutch rebuilt and bottom end apart. Running 40 to 1 gas oil ratio::) Glad to hear it run again.
Probably gonna hear a million opinions on this so I'll throw mine out there. I just got done putting a fresh top end on my 'Piner. I plan to start it & let run/idle until warm then let cool for a couple of hours (heat cycle). I'll repeat this process 5-6 times, then take it out and run it under a light to moderate load for around 15 minutes while checking for possible motor problems (jetting/timing/trans/clutch...). Pull the plug and check color. If all seems good I'll do it again a few more times before subjecting the bike to heavy loads and/or high RPMs.
Pete Petrick
175 Jackpiner
Slow but Good
Good idea to check the head torque often during the break in process.
Steve Minor