Quote Originally Posted by plumpurpleplym View Post
aba-so-looootly on the seat of pants ? might be 15 0r 20.when I start cold she brakes the tires a little and barkes when she hits 2nd.when she runs for 2 min. wont burn out at all.
I agree that underhood temps can cause all sorts of problems, but two minutes of warming time shouldn't be getting that hot, seems to me, and it sounds like it's pretty consistent. Could it be as simple as your carb jetting? Cold start, choke plate closed, rich mixture and good power; and two minutes later power loss, maybe as your choke plate opens and you lean out with unrestricted air flow? Just a thought - how do your plugs look?