Been since last March and still haven’t found it. And don’t have the $$ to keep taking it to the mechanic when it doesn’t act up for them. But I may try again soon because I know if it doesn’t mess up they can’t fix.
Here are what the symptoms are. Intermittent problem. Usually 1 or 2 times a trip. Once started the engine emits a slight squeaking noise. Hard to get to plane but if you do it’ll only run about 4000 rpms with some skipping. Sometimes you hear a popping sound while running but it’s hard to hear. Pull back the throttle to idle and the rpms surge back and forth. And most time pulling back to neutral causes the engine to stall. It’s at that point where the engine emits a growling sound. Almost sounds like it’s sucking air? Sounds like a leapord. But over the next minute or two the pace of the growl slows down until it’s just a tick.tick...tick.... With the cowling off it’s a ticking sound that’s about 5 ticks a second(pretty fast initially).
Now after you fish that spot you start it up and it may run like brand new. The last two mornings I fished it was tougher to crank. Almost like it wasn’t getting enough fuel. And the engine smoked when it normally never does. Also, when you remove the spark plugs they are filthy. Normally dry but I have seen oil on them at times.
So far I have checked compression. Changed fuel filter, fuel line, removed and emptied fuel tank. Changed air filter, plugs, all 3 coils. One mechanic replaced the thermostat and poppet valve. And the first time I started it after that it acted up. I just sent the ECU to Simon Motorsports (it was reflashed 4 years ago) and Eric said there were no problems with that( I appreciate his honesty). So that ships back next week and I move on to the next idea. I’ve been told by people it’s the fuel pump, reed valve(s), compressor, dirty fuel rails. So I’m hoping my best attempt yet to describe the problem yields a more accurate thought on what it is exactly. Like I said I don’t wanna keep sending it off and paying labor with no results. Thank you!