ceweaver
09-02-2008, 09:13 PM
I wish I didn't have so many questions for the group (by the way, I'll be joining shortly), but my Tri-Pacer isn't cooperating. Here's what we've (my IA and I) have been experiencing and what we've done:
- Flew with my kids about 4 weeks ago and we went up to 5500 feet and as I pulled power from ~2450rpm to ~2350 the engine began to run rough and lose power: 1) pulled carb heat and dropped to ~1900 - thought carb ice, but didn't get increase in RPM like expected. 2) Full power, less than 2500, and smoothed out. This happened a couple more times
- 2 weeks later (Disney and a cold) I mentioned the above to IA and we test flew it. At 2500 feet and 2400rpm we pulled power back to 2300 and it ran rough. Pulled carb heat and had substantial drop (400rpm). Full power, still 2450, and leaned the engine and got almost a 200 rpm increase. We pulled carb heat at 2300 and got the drop to 1900 and then leaned it and it took it back to 2300. Did a mag check too and had almost 200 rpm drop at 2400 on the right, but only about 125 on the left.
IA hoped it was a primer issue causing it to run rich, but thought it might be a plug breaking down under load. We pulled plugs and they looked good, but changed with an older set I had anyway. Flew and same thing. Then pulled primer and plugged it off. Same thing again.
Figure it's now the 20+ year old accelerator pump so we ordered a carb from Spruce (hence all the carb questions I was asking earlier). Got it put on today and flew it around the pattern once and still got about a 125rpm increase in RPM on downwind. I didn't get as much testing done as I wanted because I was more concerned about making it around the patch...plus was running out of daylight. I have a bad feeling that nothing has changed, but we're going to test fly tomorrow too and do the other test that I did before the change. One other thing is I'm getting just under a 200 rpm drop during my runup on the right mag and about between 125 and 150 on the left.
I think that's all that we've done. It sure seems like it is running rich, but the plugs all look really good according to IA.
Any ideas? :?
Thanks!
- Flew with my kids about 4 weeks ago and we went up to 5500 feet and as I pulled power from ~2450rpm to ~2350 the engine began to run rough and lose power: 1) pulled carb heat and dropped to ~1900 - thought carb ice, but didn't get increase in RPM like expected. 2) Full power, less than 2500, and smoothed out. This happened a couple more times
- 2 weeks later (Disney and a cold) I mentioned the above to IA and we test flew it. At 2500 feet and 2400rpm we pulled power back to 2300 and it ran rough. Pulled carb heat and had substantial drop (400rpm). Full power, still 2450, and leaned the engine and got almost a 200 rpm increase. We pulled carb heat at 2300 and got the drop to 1900 and then leaned it and it took it back to 2300. Did a mag check too and had almost 200 rpm drop at 2400 on the right, but only about 125 on the left.
IA hoped it was a primer issue causing it to run rich, but thought it might be a plug breaking down under load. We pulled plugs and they looked good, but changed with an older set I had anyway. Flew and same thing. Then pulled primer and plugged it off. Same thing again.
Figure it's now the 20+ year old accelerator pump so we ordered a carb from Spruce (hence all the carb questions I was asking earlier). Got it put on today and flew it around the pattern once and still got about a 125rpm increase in RPM on downwind. I didn't get as much testing done as I wanted because I was more concerned about making it around the patch...plus was running out of daylight. I have a bad feeling that nothing has changed, but we're going to test fly tomorrow too and do the other test that I did before the change. One other thing is I'm getting just under a 200 rpm drop during my runup on the right mag and about between 125 and 150 on the left.
I think that's all that we've done. It sure seems like it is running rich, but the plugs all look really good according to IA.
Any ideas? :?
Thanks!