All - my ZDZ 80RVJ runs well and transitions quickly and cleanly but I have one problem.... The engine idles a bit higher than I'd like. I can run it around 1800-1900 rpm with reliable and consistent results. If can slow it down to 1500 where I'd like, it will idle all day, unless the throttle is chopped too quickly. Example, idle to full throttle good. Full throttle to idle slowly, good. Full throttle to idle quickly (chopping) the idle will drop very low or stall, if it keeps chugging after the throttle is chopped, it will almost die and then slowly speed up to the desired idle. Everything else seems fine. The engine has abit over 5 gallons through it so far.

Additional info...I am running Mobile1 synthetic at 40:1 and a Vess 27A prop. This engine also shows the same symptoms when running my PT Models and Mejzlik 26X10 props. The 26" props turn up around 6500-6600 static, the Vess 27A turns 6100 static but pulls like a freight train. Any thoughts? Could a fat high speed needle cause this?