Forget vacuum, its fine, start looking at other things. I agree, a 180 thermostat is a must. You might have a partial fuel blockage somwhere as well. I had a quite similiar problem, pulled the top of the carb bowl and found what looked like a wheat hull paritaly blocking the float valve inlet. (Carter W-1) Starving the engine at peak demand. WOT, reduced flow can't keep up, bowl empties, engine starts cutting out. Let off, bowl refills, runs fine.
Last edited by Drydock; 03/15/2012 10:00 PM.
