WyoDave
Well Known Member
My 6 has an O360 with Ellison TBI, CS Hartzell, and mags. It starts fine and runs well at what I consider normal cruising around altitudes (8-10K). EGTs/CHTs are pretty even. However, at altitudes starting around 11K up to 14K it will initially be ok, but after 10 minutes or so it is progressively rougher with temps getting farther apart. Adjusting mixture, throttle, or RPM doesn't help, although in the initial stages of the problem I sometimes find a spot that is briefly better. When I come back down the engine begins to run smooth again. Now, I'm severely lacking in anything resembling wisdom or expertise in this area. But it's as if the ignition can't fire the mixture at higher altitudes. Maybe like plugs fowling, then clearing when I come down. I'm not saying that's what it is, just how it "seems". Do mags get "weak" eventually? Is mixture harder to ignite at altitude?
If it matters, the lowest place around here is the airport, which is at 7100'. My typical cross country (PNA-SHR) requires clearing some pretty tall rocks. Thus the need to get up high for awhile.
Any suggestions? I'll probably pester aerhed about this when I get the chance, but thought I would post here to start. Thanks!
If it matters, the lowest place around here is the airport, which is at 7100'. My typical cross country (PNA-SHR) requires clearing some pretty tall rocks. Thus the need to get up high for awhile.
Any suggestions? I'll probably pester aerhed about this when I get the chance, but thought I would post here to start. Thanks!