FSPilot747 From United States of America, joined Oct 1999, 3599 posts, RR: 13 Posted (10 years 10 months 2 weeks 3 days 21 hours ago) and read 10702 times:
I should know this, but I haven't been in this situation in a couple years.
What exactly do you do when your RPM drop exceeds 50 RPM during the run-up magneto check (in regards with cleaning up the spark plugs)? I would ask one of the instructors at the airport, but I'm not gonna be there for a while. I have an idea of what to do, but I want to be certain before I end up in that situation.
Flyf15 From , joined Dec 1969, posts, RR: Reply 3, posted (10 years 10 months 2 weeks 3 days 18 hours ago) and read 10636 times:
What you're refering to is fouled plugs. I've had it happen to me a few times. The engine will be running fine, upon mag check, when going to left or right the engine will drop oh say, 300rpms, and get pretty rough. To take care of it (burn it off), run the engine up to full power and lean out the mixture and maintain that for a minute or two. Go back and do another mag check. If everything goes as it should, you'll be good to go. If its still running rough (I'm just guessing here, it hasn't ever continued to be rough for me), I suppose you could try to burn it off again, but its most likely something else.
Sllevin From United States of America, joined Jan 2002, 3376 posts, RR: 6 Reply 4, posted (10 years 10 months 2 weeks 3 days 17 hours ago) and read 10618 times:
I agree with with Flyf15, with the exception of running the engine at full power. You'll generate extra propeller wear, and at high power settings running lean can lead to detonation (unless you are SURE you are significantly lean of peak).
At 1700rpm, detonation from running close to peak is very limited, and you aren't spinning the tips nearly as fast near the ground. Expect to run the engine for about 2 minutes to clear the fouling. Beyond that, if it hasn't cleared up, you may have some additional issue.
FSPilot747 From United States of America, joined Oct 1999, 3599 posts, RR: 13 Reply 6, posted (10 years 10 months 2 weeks 3 days 16 hours ago) and read 10582 times:
So basically, instead of having your mixture full rich, just lean it out as far as you would over 3000 ft? ..or more than that? Then full power? I remember now the full power and mixture lean, just didn't remember how much.