2015 RV12 SLSA with 912ULS, 130 hrs. History: Went to start, fuel blowing out of overflow on #2 carb. My A&P somewhat familiar with Rotax, advised float issue, since aircraft annual due in month, carbs require 200 hr overhaul, both decided to just send both carbs to Lockwood Aviation for overhaul. Reinstalled, initially ran ok, challenges getting carb synch completed. Engine run-ups deteriorated after intial test run up. Started to get over 300 rpm drop on each side on run up at 130-140 degree engine temp, rpm drop reduced to about 200 rpm per side at engine temp 190F. Ran ok in flight, produced respectable power, but synch just not perfect. Removed plugs, all black velvet color, no wet appearance. Reinstalled new plugs from Lockwood, .028” gap. (A&P indicated initial reinstall of carbs choke setting not right, could have caused rough engine and spark plug issue). Started perfect, did runup at 130F, approx 70rpm drop each side. Taxi for takeoff, additional run up, all good. In flight, noticed carb synch ok, not perfect. All engine parameters within limitations, normal. Landed. Did run up, rough engine, RPM drop near limitation. Observer indicated during my initial runup, light exhaust smoke noted. At this point, not sure where to go. All spark plugs removed during annual inspection, prior to rebuilt carbs, perfect condition.
Any suggestions?
Any suggestions?
