Im getting a os 50sx and was wondering what you guys are running and what rpm. Thanks

THIS IS A VERY STRONG MOTOR. HOWEVER THERE IS A PROBLEM WITH THE REMOTE NEEDLE . IT STAYS FULL OF AIR BUBBLES. I REPLACED MY CARB WITH A SUPER TIGER 60 CARB AND IT RUNS GREAT! 15,000 WITH A 11-5 MA AND IS EXCEPTIONALLY QUIET. I WILL SEND MINE BACK OVER THE NEEDLE THOUGH AND SEE WHAT THEY SAY. HOWEVER THIS A PROBLEM WITH MOST OS REMOTES.

I get 15.2K with a TH .46 on a mousse can pipe, and 3% nitro. This engine is prob capable of spinning a much larger prop. 12x4, 12x6, 11x8 or so.

I have had two, never had a problem with the remote needle valve, bubbles or anything. Running a 12 x 4 at around 11500 and a 12.25 x 3.75 at around 12,500. Incredible 2 stroke engine, will idle for hours and will not flame out.

I have no tach readings, but it is my very favorite 2 stroke engine. Mine uses a 12x4 fun fly prop and Ultrathrust muffler. About 50 flights on it, and yet not one deadstick. Idles for hours and doesn't load up at all. I am using Wildcat YS 20/20 fuel.

I'm running an APC 12.25 X 3.75 Power MASTER 15% stock muffler at 12,600 on a Morris Hobbies sledge 540 great combo for 3D Hovering and Torque rolling. and with my JR 10 X I can desensitize the throttle response RPM around the hover stick position for precise RPM control 1 ft off the ground in a hovering toque roll. good engine choice, very reliable once set never quits until you want it to!!!!

Wow that is an awesome picture. But man it looks dangerous.
I would never get that close to a spinning prop arc (especially @ 12,600) but I appreciate you doing it for us.

I second the 50sx. I am running a 12 1/4x3 3/4 apc, macs tunned pipe and it just screams!! You can hear the tips of the prop burning on a high speed pass... Fun stuff I tell ya :thumup:

Still breaking mine in, haven't gone for serious power yet.

Wildcat 15%
TopFlite 11x7
5900 feet altitude
12,600

Mine had the air leak in the needle valve. It was the plastic washer under the cap that plugs up the other spot you can screw the needle valve into. I put a washer from a glow plug in instead of the plastic one and it fixed it.

When I was still breaking mine in, it started cutting out at high RPMs. In my ignorance of many things glow, I thought the air bubbles between the needle valve and the carb were the problem. It turned out to be a problem with the glow plug (too cold and possibly went bad prematurely). Until a new plug was tried. I did all of the following:
Had a replacement teflon gasket for the plug screw mailed to me (same thing you were missing mike).
Installed foam on three sides of my fuel tank (which I probably should have done anyway.
Installed fuel line clips everywhere I could.

I still see bubbles, maybe not as many, but I have not had any obvious performance issues with the engine.
Another benefit of the clips is that I installed one on the line from the muffler, that seemed to cut down on the amount of oil that ended up on my wing. I have also tried another trick which keeps my wing and fuse even cleaner. Silicon glue. I used it on the muffler and where the muffler meets the engine. It will withstand temperatures that would practically melt the glow plug. Since all the surfaces are metal, it doesn't really bond, so you can still easily disassemble stuff.

I had surging issues with mine running an APC11X6. After cleaning carb, needle valve etc I still couldnt get it to haul like it was after running it in. To get semi decent performance from it Im now running an APC10x7 prop and tached it today for the first time. After starting and letting it idle for about a minute I went to full throttle and got 13400rpm, BUT after about 30 secs it came back to 12800-13000. Im NOT happy with mine at all really and am considering replacing the ring and running it in again to see if I can get better. Ill try the 11x6 back on it and tach that soon as well, before replacing the ring.

Put my APC 11x6 back on it today. It only gets 11500rpm. NOT enough from what I see here. ? ? ? ? ? ?