ORIGINAL: hsukaria
I got back to testing my used Fox 74 Eagle IV on the bench. This time I changed the fuel to Morgan Omega 5% with 15% synthetic oil and 5% castor oil. I used a Top Flite wood prop 13x6. It ran well with good transition, but still rich at the high speed with some transition hesitation close to the top.
WOT 10500 RPM without trying for maximum setting. Still quite rich.
IDLE 2000 RPM (could go as low as 1800 rpm, but a bit unsteady). It would idle indefinitely and then transition to WOT with slight hesitation due to rich high end.
Now the question is: Will it stall while flying on part/low throttle? I can't tell, I am not experienced enough, but it happened to me before.
BTW, I don't have a plane for this engine anymore. I have to find a cheap and simple airframe for it to do my testing before I put it in a warbird model.
I don't have any reason for my engines to idle below 2,400 to 2,600 RPMs. That might be your problem, trying to idle too slow. Now granted after a engine is run in really good, it'll likely idle slower. Now granted if you are flying off of pavement, then a lower idle might be more useful, but I don't remember needing to idle at 2,000 rpms or less even then, when I flew off of hard pavement before.