ST X.11

Well, I was given a new ST X.11 - blue head - without the muffler. It is definitely an ABC as I can feel the pinch at TDC. It has a venturi and needle valve.

Is this engine usable for sport UC - and if so - what plane(s) are recommended?

Is there any thing I can retrofit for a muffler?

Should be fine on a Jr Flitestreak, Shark 15, or Magician 15. don't know about a muffler, but someone should be able to make you one.

Is this a ST X11 plain bearing or ball bearing? Actually it doesnt matter.I have both.These engines really turn. I can't recall my tach readings but I use a plain bearing X.11 on a 450 sq " free flight model. This model climbs fast straight up. Very nice engines. I don't know how much a muffler would work to tame it down. One of my X.11's came with a muffler. I never used it and evetually gave it away to someone who put it a Tigre other than the X.11. It might be mufflers from smaller Tigers will fit. One of my engines came from Tower Hobbies. Maybe they have a muffler laying around. Andy