I'm currently having some growing pains with a DZ 140. I have been running other YS engines for years with great results but this one has me a bit stumped. Being that it does not pressurize the fuel tank it is a bit different then other YS engines or any other glow engine I have ever run.

So here is what is going on. Fuel is Wildcat 20/20 all synthetic, plug is OS F and prop is Engle CF 16x10 three blade. I do have the YS filter clunk in the tank and a filter prior to the pump.

Top end is great, I have the engine mounted on a Circus Hobbies Reed Falcon that weighs 9 lbs. I have not put a tach on it but running slightly rich it sounds in the ballpark of 8,000 to 8,500. The issue is that the mid range is lean. We all know what the YS lean transition sounds like. On my 115 WS I richen up the high speed needle and the detonation goes away, no big deal. With the 140 in order to do this the high speed needle has to be so far open that there is no power increase between 1/2 and full throttle. Obviously it goes through fuel really fast this way and that was cause of my first dead stick today. So I went back to peaking out the high end but still rich from peak and the poor transition is back. Next option was to richen up the low end. I adjusted the pump regulator in until the transition was flawless. The engine now runs flawless except.............the idle IMO is way too rich. When I remove the glow driver I have to have the idle rpm rather high and then the rpm drops much more then what I am comfortable with. Although the last flight today was Flown this way and until a fuel line came off the regulator it ran great. Dead stick # 2 and a scuffed wing tip....ugggggg.

The fuel line that popped off is the one that runs from the regulator to the carb and it did have a fuel line clamp on it. Anyone else have this issue? The next thing I plan to try is upping the nitro to 30% to help my confidence with the idle rpm drop without glow. Any other ideas?

Thanks in advance.