Despite regularly leaning 1-1.5" back on the mixture on the ground, 5CA has developed a nasty habit of fouling on cylinder #4 during longish taxis (say 10 min), and cylinder #6 when held a long time for release (say 20+ min, such as at Dorval this Wednesday and Frederick after the AOPA Fly-In). I'd think it cannot be good for the engine to idle so rough, either.

It's time for a 50-hour check anyway, but does anyone have an idea why this phenomenon has so recently worsened? It's unnerving to have to constantly clear the engine before the takeoff roll.

Nothing in flight shows a problem -- it's the usual smooth IO-540, and oil consumption has been (if anything) better than ever.

Thanks,

Jon Guy
114B #14586 N585CA
NE Philadelphia (KPNE)