Just as important...what makes you think your runnning lean.motor heating up?idle/ WOT? Now don't get me wrong,putting the motor on a dyno's a good idea..but i'd feel like a fool if the problem was the low-speed stuck ,open-barrel valve not right,weak fuel pump,pin hole in suction side line fuel systm ,or even the timing retarded caused the motor to heat...a more clear description of the issue and some one might have a solution for you..good luck