Just purchased an FL OS91 4 stroke, the pumped version. In trying to break it in I followed the instructions, opened the needle valve 3 1/2 turns and started the engine but it would hardly run. I ended up with the needle valve only open 1/2 turn from fully closed.

After running a couple of tanks through I did one flight but it seemed to not be able to get RPM up. In attempting to tune up the engine I ended up being able to run the engine with the needle valve FULLY closed. It would idle fine and build up to max RPM. It would run at about 1/4 turn out but wouldn't build to full RPM.

So, I can't figure out what to do. It looks like the pump is putting out too much pressure but there doesn't seem to be anything I can do about it. Also, I seem to be going through plugs. What happens is that I'll start the engine (about 1/2 turn out) and it'll run but if I pull the glow starter off it'll quit running. I put a new plug in and seems fine. When I pull the plug, it lights up just fine. Looks like either the platinum has somehow come off or the pump is quenching the plug.

Any help would be apprciated.