OK, so I had the stuck valve problem which was real, and is now fixed. Compression is good now (115 on both sides with an automotive compression tester). But I'm still having trouble.
Today I spent a long time flipping the prop. It would pop occasionally, usually on the LH cylinder, but not start. Finally it did start and I let it run around 1500 rpm to warm up, but then it quit again. Kind of like last time, but I still had good compression on both sides. Kept trying various combinations of choke or not, again a long time, and eventually it started again. This time it kept running, and I let it run for 20 minutes or so to warm up. Full throttle seemed fine, 3000 rpm which is what it was before, and OK throughout the range. Decided to go ahead and fly, jacket, scarf, gloves, harness, etc., as it kept running fine. Taxied out to the runway, made the unicom call to depart, advanced throttle to taxi onto the runway... and the engine quit. Pushed it back to the hangar, again spent a long time trying to start it. Again got it started once, let it run around 1500, and after a few minutes it quit again. AAAAARGH!!!!
Several times I pulled the plugs and laid them on the cylinder with the wire connected. I have spark, hard to say whether it's a good "fat" spark because it was bright and sunny. But the plugs seem dry, even after enough cranking with the choke on that it should be flooded. When I crank it with the choke on, fuel drips from the carburetor, so it's pulling fuel in... so why are the plugs dry? Finally I gave up and went home, enough for one day.
Two things to try tomorrow: Recheck the valve clearance (since I had the heads off and lapped the valves), and try ether starting fluid. But when it did run, it ran fine, so it doesn't seem likely it's something hard mechanical. Then pull the carburetor off, maybe there's some crud in it (it did sit for 10 years). I would have done the above but I didn't have the right tools with me. Or maybe the old Slick mag is weak, I'm not sure how to judge it. The timing is correct.
When I contacted Slick for information about the mag (model 2316) when my A&P was questioning how to inspect it, they had nothing because it's old (23 years, but only 350 hours), and advised I replace it "just because it's so old." Maybe I should, but I hate to throw expensive parts at an engine as a diagnostic tool.
Right now I'm going to crack open another beer and think about it, but I'd sure welcome any inspiration.
Dana
Today I spent a long time flipping the prop. It would pop occasionally, usually on the LH cylinder, but not start. Finally it did start and I let it run around 1500 rpm to warm up, but then it quit again. Kind of like last time, but I still had good compression on both sides. Kept trying various combinations of choke or not, again a long time, and eventually it started again. This time it kept running, and I let it run for 20 minutes or so to warm up. Full throttle seemed fine, 3000 rpm which is what it was before, and OK throughout the range. Decided to go ahead and fly, jacket, scarf, gloves, harness, etc., as it kept running fine. Taxied out to the runway, made the unicom call to depart, advanced throttle to taxi onto the runway... and the engine quit. Pushed it back to the hangar, again spent a long time trying to start it. Again got it started once, let it run around 1500, and after a few minutes it quit again. AAAAARGH!!!!
Several times I pulled the plugs and laid them on the cylinder with the wire connected. I have spark, hard to say whether it's a good "fat" spark because it was bright and sunny. But the plugs seem dry, even after enough cranking with the choke on that it should be flooded. When I crank it with the choke on, fuel drips from the carburetor, so it's pulling fuel in... so why are the plugs dry? Finally I gave up and went home, enough for one day.
Two things to try tomorrow: Recheck the valve clearance (since I had the heads off and lapped the valves), and try ether starting fluid. But when it did run, it ran fine, so it doesn't seem likely it's something hard mechanical. Then pull the carburetor off, maybe there's some crud in it (it did sit for 10 years). I would have done the above but I didn't have the right tools with me. Or maybe the old Slick mag is weak, I'm not sure how to judge it. The timing is correct.
When I contacted Slick for information about the mag (model 2316) when my A&P was questioning how to inspect it, they had nothing because it's old (23 years, but only 350 hours), and advised I replace it "just because it's so old." Maybe I should, but I hate to throw expensive parts at an engine as a diagnostic tool.
Right now I'm going to crack open another beer and think about it, but I'd sure welcome any inspiration.
Dana
