[Mark Hislop]

JR:

So far (4 years in my 73 P337) I've never had the problem. I have one factory reman (about 150 hours on it now, replaced an engine that had 1000 hours, running good but the crankcase cracked) and one mid-time (800 hours) engine. The oil in the mid-time engine gets black very quickly after an oil change, which I assume is carbon from the combustion process. I use Aeroshell 15W50 year round, except when breaking in the new engine, when I used mineral oil. I do not lean aggressively, since I feel that gas is cheaper than maintenance. Unfortunately, I don't put as many hours on the plane as I would like...probably 50-75 per year. Based on all of that, you would think I would be a prime candidate for this carbon fouling problem. However, even though it hasn't happened to me, if GMAS says it happens, I believe it. Maybe it's like gear up accidents...there is those that have and those that will.

Let us know what your 414 friend has to say.

Mark