TT Pro 40 engine problems
 

I have a TT 40 Pro that I plan to use for Club 40 pylon racing. It is my second TT Pro 40 engine. The first works flawlessly. This second engine has problems. After a few flights the engine sat for about a month (with afterun oil) Back to the field I fired it up, all appeared normal so I taxied out. When I accelerate to takeoff the engine reves and the plane accelerates but the engine suddenly dies. Back on the test bench I can duplicate the problem so I switch to a new glo plug. The engine would accelerate smoothly and then suddenly slow and stop unless I backed off on the throttle. I dicovered that I could delay the problem by opening he needle valve but this does not solve the problem. With the needle valve open 3.25 turns I noticed that the engine was not sounding any different at any throttle setting over about 2.0 turns. It is hot but not sure what overheating would feel like. Is there a temperature I should not exceed?

I was using a Master Aircrews 10x6 prop.
15% cool power fuel.
I tested fuel and pressure line and found no leaks.<br type="_moz" />The needle valve assembly is solid and I do not see any leaks.

Any suggestions?

<br type="_moz" />

RE: TT Pro 40 engine problems
 

I think that the engine might still be a little bit lean. Is it extremely hot when it shuts down?

I see a lot of guys at my field peak their engines on the ground thinking that they're getting the most out of them. They reject the explanation that the engine will unload in flight and, if already peaked on the ground, will lean out and die. Try the pinch test before you launch again - i.e., just a momentary pinch of the carb line. If you don't get a noticeable increase in RPM then you're still set too lean.

Just my $.02

Bob