Hi Gary, According to the Continental Operator's Manual, Form X30012, 1980, p. 15, checking magnetos at 1700 RPM there should be no more than 75 RPM difference between mags during single-magneto operation, and maximum allowable drop between "Both" and an individual magneto is 150 RPM. "Normal" is 25-75 RPM...[more] usually indicates a faulty magneto or fouled plugs.
Minor fouling can usually be cleared by advancing the throttle to 2200 RPM and leaning until RPM peaks, holding that setting for ten seconds before returning the mixture to full rich. [Do not allow engine to overhead during ground operation.] Regards, WRB -- On May 2, 2009, at 13:09, G. Davis wrote: > > What do you all use as a guide to how much different your RPMs are > during run up, on each side? I just had my mags cleaned and points put > in one of them, and I have about 100-125 RPM difference. Is this > permissable, or do I need to look further to get them closer? > Thanks for reading this note. > Gary
