Manchu16
Active Member
I was hoping this group could help. Recently bought a 9. In flight at cruise, I get an occasional miss or stutter. So quick, my passenger doesn’t notice and my engine monitor does not catch it. Literally like it just doesn’t fire on cylinder on one revolution. It doesn’t always happen, but some flights it may do it 5 times over a 15 min period. It is noticeable enough to get me wondering what is going on.
O-320 160hp, one bendix mag (300 hrs since oh) and 1 PMag (300 since new).
Enriching mixture does not prevent it.
Running elec Fuel Pump doesn’t prevent it.
I have not done an extended single mag cruise test as it doesn’t happen that frequent and concerned about running on a single mag for 15+ mins.
EGT/CHT appear normal.
A&P checked;
Compression 75 cold across all cylinders. Borescope clean. No visible damage to plug wires. Mags timed. Plugs looked great after 40 hours since last cleaning. He is at a loss. Recommendation to get both mags serviced/overhauled. Then replace wires if that does not fix it.
Before I start sending parts off for overhaul and replacing items I was hoping this group may have other ideas on what to check or may have experienced something similar.
O-320 160hp, one bendix mag (300 hrs since oh) and 1 PMag (300 since new).
Enriching mixture does not prevent it.
Running elec Fuel Pump doesn’t prevent it.
I have not done an extended single mag cruise test as it doesn’t happen that frequent and concerned about running on a single mag for 15+ mins.
EGT/CHT appear normal.
A&P checked;
Compression 75 cold across all cylinders. Borescope clean. No visible damage to plug wires. Mags timed. Plugs looked great after 40 hours since last cleaning. He is at a loss. Recommendation to get both mags serviced/overhauled. Then replace wires if that does not fix it.
Before I start sending parts off for overhaul and replacing items I was hoping this group may have other ideas on what to check or may have experienced something similar.
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