I have a Megabaja and after 2 gallons the stock engine lost compression and began hard to start. Had to let it cool and restart. I bought a surefire .32 and it ran awesome then after 1 gallon...same thing I just tore it down for inspection and all looks good. No scratches in piston etc. Put it back in and started it. Seems to run fine but gets very hot at idle and takes alot of fuel prime to get it started....still low compression. ...I am used to aircraft and helis and am new to cars/trucks....am i running them too hot/lean? Do i tune them with a temp gun not by smoke?ear?....please help

sounds like u cooked your motors, to tune, smoke isnt the best way, because different fuels have different oils and oil contents, so some will smoke like a chimney,, some wont smoke much at all.

Just tune by ear, its the best way, and if your not so good at tuning, a temp gun is a pretty good investment, it will help u from over leaning the motor