i am sure this has been addressed many times before. i could not find a posting however. my 91AC runs very good and powerful at peakandfull throttle and transitions well. no problems there.but i cannot get it to idle smoothly or dependably. ihave tried "everything".it is installed in an aeroworks extra 260 (60 size). i have sentthe engine to YSservice twice in the past couple months. the first time a pushrod, bearings, diaphram, and glow plugwere replaced. butwhen i received it back theidle problem remained. i sent it back to YSservice for a 2nd look. this time the disc valve was found to be loose and itwas tightened. i was then toldit was runningok at the shop.however, the problem continues. itwill idle for 30-45 secs on the bench (although erratic and lots of vibration) at about 2300RPM. if i fly the engine"kills" when throttling back to land. i have upped the idle to as much as 2600 RPM to try to keep it running. my fuel is 20/20 YS. it is fresh. there are no leaks in the fuel system. pressure is good.i fly at 5800 ft above sea level.
i am wondering if someone "out there" has any ideas or suggestions. thanksmuch for your help. PS this is my first YSengine.