Originally Posted by Ashley Cobb
Is it common for a nitro engine to run really hot when its being run in?
It is richened up to 3.5 turns as in the manual, and there is a faint smoke trail...
break in period = follow the manual. 80C - 90C is good enough for break in process. You could richen by another turn if you want. Break in with low temp usually you risk the piston sleeve to short live.
After break in :
Yes, hot means good for engine ( 95C - 115C ). Don't believe the smoke trails. Use temp gun and watch and hear how the engine perform on short straight ( exiting corner and accelerate ) and long straight.