[carguy614]

Hello all,

Thought I would poll the group on an unusual engine issue. I now have 24 hours on my 9A with Superior XP320 and the only issue has been a bad mag check, misfire, on number 4 lower plug. Easily identified with CHT/EGT during runup. I have always been able to clear it with a lean pull in 40 seconds or so, and inflight performance has been real good. Decowling for my first oil change and an obvious plug inspection and cleaning, I found no's 2 and 4 lower plugs wet with fresh oil. Hmmmmm. Borescope reveals no abnormality, oil consumption has been remarkably low, at 2 quarts total through the break in phase, and absolutely no burned oil deposits on the plugs at all. Seems that oil must be running down the guides after shutdown. That leads me to believe that a drainback issue may be the problem, so I removed the valve cover to check the drain pipe, and all seems well. I am using an oil separator with the return plumbed to the accessory case on the opposite side. A call to Superior has led to no real answers.
Anyone else seen this??
Regards.....Chris

 

[mahlon_r]

Assuming you have the correct spark plugs, to me it sounds as though those cylinders have not fully seated yet. Keep the power at 65-75% in cruise for another 15-25 hours and see if they dry up. Do they look like they are full of oil or just shinny like you sprayed them with WD-40. If the later, you may be able to salvage the break in. If they are really full of oil you will likely need a hone and re-ring on those cylinders.
Good Luck,
Mahlon
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