Howdy,
I am having an issue with a moderate high time (1800 hrs) O-320. I realize its time for a rebuild, but not sure if this is a minor thing or not.
was on short final and had a pretty good backfire, landed and started to trouble shoot. symptoms: backfiring at low RPM..goes away at about 1600 rpm runs smoothly. backfire is consistent between L/R/Both mag switching. bottom plugs all good. compression checks all in the upper 70's. Took apart carb, 2 piece venturi solid as a rock. did have a broken primer lead into #4 cylinder..fixed it but problem is still there. Took off rocker covers and no broken springs. Haven't checked valve lateral movement tolerances but that is prob next on the list. Valves seem to be moving freely. Not bad gas..tanks/sumps clean, carb clean. Not a plugged exhaust either, checked that. Just trying to bounce this off you guys for anything obvious I may have missed. Thanks for the help!
I am having an issue with a moderate high time (1800 hrs) O-320. I realize its time for a rebuild, but not sure if this is a minor thing or not.
was on short final and had a pretty good backfire, landed and started to trouble shoot. symptoms: backfiring at low RPM..goes away at about 1600 rpm runs smoothly. backfire is consistent between L/R/Both mag switching. bottom plugs all good. compression checks all in the upper 70's. Took apart carb, 2 piece venturi solid as a rock. did have a broken primer lead into #4 cylinder..fixed it but problem is still there. Took off rocker covers and no broken springs. Haven't checked valve lateral movement tolerances but that is prob next on the list. Valves seem to be moving freely. Not bad gas..tanks/sumps clean, carb clean. Not a plugged exhaust either, checked that. Just trying to bounce this off you guys for anything obvious I may have missed. Thanks for the help!