I recently purchase a used heli with a OS .28 engine in it, it starts fine but when I remove the glow starter it runs for a few seconds and then quits. Can anyone help?
Thanks in advance
Rob

You either have a bad glow plug or it is running too rich. Probably the glow plug unless you have changed the low and high end needle valve settings......

I am assuming thats the screw inside the throttle linkage?
Would you know where I can get info on how to properly adjust it?

I had this same problem on an O.S. 91 FX mounted inverted. The engine would run fine with the glow starter attached, but would quit after about 5 seconds with it off. I tried everything with the needle settings, etc. It would seem to run fine at full throttle for a while, but at anything less than full throttle, it would slow down, and then quit. Like throwing a switch. I took this engine off of the plane, bought a Saito 100 and put it on. It runs perfectly. ( I really wanted that one on the plane anyway, good excuse to buy one!) After this, I bought an OS .25 FX brand new. I did not have a glow plug for it, so I pulled the one off of the 91 and installed in in the OS .25 FX. I Started this engine fine, and was running it very rich, so I expected the engine to quit when pulling off the glow starter. Once the break in was done, I was trying to get a good idle, but it would quit on me the same as the 91! I suddenly dawned on me that the same glow plug was in both engines! I replaced this plug with a used one from another engine, and viola! Purrfect idle, great transition, and will run all day at 1900 RPM. This was a brand new, in package OS #8 glow plug that was bad!

Thanks I'll try a new plug

If you are not sure which screws do what, GET HELP! Hook up with some one who knows heli's. Those wonderful blades will mess you up in a heartbeat. Scenario....throttle barrel retaining screw is loosened.......then falls out from vibration.......motor goes into high idle at best......you now have an engine that may not shut down! You now pick up the heli and radio, but the heli starts to spin and that tail rotor is now headed your way! Please get some assistance. We had a guy who had his arm get really torn up from a heli, don't want to see this happen again.