Lead/Carbon fouling Continental O-200
Looking to get some insight into an incident I had on a cross country:
C150M: 1/3 of the way there, over mountains and I get a rough engine. After troubleshooting while orbiting a good precautionary spot we find its fouled plugs and decide to head home rather than continue on.
Initially i was very skeptical of plug fouling as I was only thinking of unburnt fuel or oil causing weak spark. This didn’t make sense to me with a properly leaned mixture setting. In later research I found that fouling from carbon or lead deposits can happen too which would explain why this happened despite leaning the mixture.
I’ve read that a lot of pilots will taxi with a lean mixture as well as progressively lean in the climb past 3000’ as a preventative measure. My school’s SOP calls to taxi at full rich and not lean until reaching cruise altitude. Full rich at top of descent too. This would be more conductive to plug fouling, no? Would it be advisable to not do this or is this a matter of preference?
Let me know if I’m missing any key points.