compound air

For the past two weeks a problem has plagued a friends H9 1/3 CAP with a BME 102. On down lines the engine will quit resulting in a dead stick landing. Have changed props to a Bolle composite and also adjusted the idel up to 2200 RPM with the same results. If anyone has some suggestions I would appreciate before the CAPs life is pre-maturly ended as a result of the failures. Thanks Ed

DMcQuinn

My Feedback: (13)

I had a similar problem with my 3W 100. At a fast idle, when I pointed the nose down, the engine would slow down and quit within a second or two on the downline. Even just a 25 degree downline would cause the engine to stutter and sometimes quit. I assumed a fuel delivery problem (e.g. clunk stuck in top of tank, etc. ). But I realized that any tank problem would probably not be so quick. In other words, even if the clunk was exposed to air, it would take a few seconds a a fast idle before the air bubble reached the carb.
My problem turned out to be an air leak between the carb and the intake manifold. The 3W engines are famous for having a warped phenolic block under the carb.
I cannot explain why this leak caused problems when the plane was pointed down, but it was very repeatable.
Look for air leaks and let us know what you find.

Geoffbob

My Feedback: (12)

I had this problem also with my Sachs 3.2. Engine ran great on the ground and in level and upward flight, but would go very lean and sometimes quit on downlines. I checked my popoff pressure, which was at 22#. I bent the float arm and cut off a bit of the float needle coil, and got the popoff down to about 10 lbs. Yeehaw! Now the engine keeps running and the midrange transition is also much better. I had to set both needles leaner to compensate; now life is good. Popoff is checked with a small thumb-operated air pump, anyone that works on watercraft will have one. Good luck!

compound air

great suggestions I appreciaste the help so far.