My carb 0320 has run rough on startup recently when temp is between freezing and 40F. Boost pump, magcheck,mixture leaner, switch tanks , none of these affects the VERY rough running. I heard some exhaust popping recently. However, as the engine warms up, it smooths out, takes a full power runnup and runs normal thereafter.
Could it be thermal expansion closes an intake leak ? If a visual inspection and checking nuts for tightness dont fix it, how do you find intake leaks.
Also, is it possible a lean idle mixture can cause this magnitude of rough running. The idle cutoff rise is about 20 RPM, not 50’ but I have not had this problem for 250 hrs until temps turned cold this year.
Could it be thermal expansion closes an intake leak ? If a visual inspection and checking nuts for tightness dont fix it, how do you find intake leaks.
Also, is it possible a lean idle mixture can cause this magnitude of rough running. The idle cutoff rise is about 20 RPM, not 50’ but I have not had this problem for 250 hrs until temps turned cold this year.