Hi all I have the 90 size SK engine. My satisfaction with this motor has been very mixed. Break in on the bench seemed to be a non event, but once put into my plane, a Sportsman Aviation Paramount 60 I have had no end of trouble with tuning. The motor is mounted inverted, but I have never had a problem with inverted motors before. The low speed needle has been wound in quite a fair way to maintain a reliable idle but in doing this I cannot get the high speed needle set rich enough, after turning high speed needle out approx 4 1/2 to 5 turns the engine to try and get rich enough it all of a sudden goes lean and just dies. Now looking through the top of the carb my low speed needle has nowhere near a 1mm gap it actually has no gap and is in the spray bar if that makes sense. I am running a 14X8 APC prop and would run a 15X6 but I do not have the ground clearance. Oh also when flying when dropping back on throttle the engine makes a ring ding ding noise like a 2 stroke motor bike which some would say indicates too lean a setting on the low speed needle but if I try to richen it, it just loads up and stalls. Please any help would be appreciated
Cheers

Scott