I have a GMS 47 with a APC 11X5 prop mounted in a Sig SE . It has lots of power, will go vertical forever. Mine idles great, transititions good, and even shuts off. Now for my problem; Unless I set it very rich on the ground (guessing 1500 below peak with lots of smoke) it wants to quit at the top of a loop. I am thinking it must be leaning out as it goes over the top, but it will go vertical as long as I want. I have checked the tank, fuel lines and clunk. It seems if it was a pressure problem it would lean out when vertical also. Anyone else have this problem? Does this engine just really unload in the air? I also have a OS 46FX and a Magnum XLS46, they are both good but the GMS puts out more power.
19 years ago