DaveHalverson
Well-Known Member
- Joined
- Mar 9, 2015
- Messages
- 223
Help! I need to know a good head clearance for my older CMB red head .21 motor. Without shims, the clearance is approximately .022-.024. At this clearance and 60% BAM fuel, I am blowing plugs on every run. I experimented with a .008 shim and it ran great without blowing a single plug. .008 seems too much though but I need to know where it should be. Thanks in advance for any advice... below is a photo of the measurement taken from the motor on a gauge.
Dave
Dave