JackinMichigan
Well Known Member
My brand new Lycoming IO-540 on my RV-10 is having excessive RPM drops when I do the magneto checks. The plane has yet flown and the engine has maybe 15 minutes of run time, but from 1800 RPM I get 100 and 230 RPM drops on the magnetos. Lycoming's manuals says it should be no more than 175 RPM overall and 50 RPM between magnetos.
One thing suggested in the manual was leaning the mixture and trying again, which I will do next time I'm out there, but I always understood that exercise was for cleaning fouled plugs. I can't see an engine with 15 minutes on it having fouled plugs (or could it?).
Any insights? My concern is that I have some sort of hardware problem that could derail my flight schedule.
One thing suggested in the manual was leaning the mixture and trying again, which I will do next time I'm out there, but I always understood that exercise was for cleaning fouled plugs. I can't see an engine with 15 minutes on it having fouled plugs (or could it?).
Any insights? My concern is that I have some sort of hardware problem that could derail my flight schedule.