Jerrygemma
Member
Thappened a week back and I am out of town so I don?t have all the details...
Rv7a. O-360 engine, bendex mags, 800 hours ttl time. Never an issue.
Jumped in to fly and for the first time ever the engine was very hard to start. It would crank and back fire every once in a while but never really fire. Went through flooding the engine and all those techniques. Finally got it going. On the run up the left mag was very rough. Leaned it out and it cleared up. Good to go. At about 100? the engine started backfiring and sputtering. Pulled it to idle and landed no problem. Taxied off and did the run up again. Left mag number one cylinder was significantly cooler get than the rest. Pull the plugs and the bottom plug was completely loaded with lead. Cleaned it out and put it back together.
Run up again at 1600 rpm and this time all was good. Went to full power and held it there for 30 seconds or so and again, sputter and back fire. Same result with the number one cylinder and the left mag cooler than the rest.
Installed new plugs. New run up.. 1600 rpm all good. Full power for 1 minute all good. Temps all good. Let?s go fly... climb out good, circle the field and all good... off to the practice area.. a couple of backfires or did i imagine that... well upon landing, short final it back fired.. on rollout the engine quit. Hard to start again but got it going. Did a run up and both mags were misfireing now and again the number one cylinder was cooler than the rest. Taxied back to the hangar and put it to bed. I had a beer.
So it appears not to be the plugs as they are new. Seems not to be the mags as both are acting the same. 100ll fuel with no contamination so don?t think it is that.
I have not pulled it apart since. Going to check compression... thinking a sticking valve maybe.
Any thoughts..
Thanks in advance.
Rv7a. O-360 engine, bendex mags, 800 hours ttl time. Never an issue.
Jumped in to fly and for the first time ever the engine was very hard to start. It would crank and back fire every once in a while but never really fire. Went through flooding the engine and all those techniques. Finally got it going. On the run up the left mag was very rough. Leaned it out and it cleared up. Good to go. At about 100? the engine started backfiring and sputtering. Pulled it to idle and landed no problem. Taxied off and did the run up again. Left mag number one cylinder was significantly cooler get than the rest. Pull the plugs and the bottom plug was completely loaded with lead. Cleaned it out and put it back together.
Run up again at 1600 rpm and this time all was good. Went to full power and held it there for 30 seconds or so and again, sputter and back fire. Same result with the number one cylinder and the left mag cooler than the rest.
Installed new plugs. New run up.. 1600 rpm all good. Full power for 1 minute all good. Temps all good. Let?s go fly... climb out good, circle the field and all good... off to the practice area.. a couple of backfires or did i imagine that... well upon landing, short final it back fired.. on rollout the engine quit. Hard to start again but got it going. Did a run up and both mags were misfireing now and again the number one cylinder was cooler than the rest. Taxied back to the hangar and put it to bed. I had a beer.
So it appears not to be the plugs as they are new. Seems not to be the mags as both are acting the same. 100ll fuel with no contamination so don?t think it is that.
I have not pulled it apart since. Going to check compression... thinking a sticking valve maybe.
Any thoughts..
Thanks in advance.