HELP! Nitro OS MAX .40 FSR not running properly
 

Hello,

I was recently given two models which I am restoring currently. One is ready to fly the other still being restored as it was never completed originally. The one ready to fly has currently fitted to it an OS MAX .40 FSR. I have replaced the fuel tank and the glow plug which I am told is the correct one for the engine.

The problem is, each time I start it, it starts pretty happily around half throttle although it does tend to wonder in rpm. If throttle is increased it can either stay running or stop. If the throttle is decreased it will stop. I can not get it to sit at a suitable idle. Please help!

Try adjusting the high speed needle valve . That would be the adjusting screw on the side of the carb , sounds like it may be a touch lean . Turn the valve out just a hair at a time till it runs smooth . Never make large adjustments , just 1/8 th or so at a time . If it still gives you a hard time, take the valve out, blow some fuel out of the carb by putting some pressure in the tank so the fuel back flushes the carb. Then clean the needle valve off and reinstall . Turn it all the way in until it JUST touches the seat then back it out 1 an 1/2 turns and start over adjusting ( slowly) . Good Luck . Red

Red Head gives good advice. Running too rich won't harm it, but running lean can. I always try to start where I know it's rich and then lean it a little bit at a time. I have found basically 5 things that will make a glow engine not run right; Bad fuel, Bad glow plug (even if it glows it may still be bad), Settings not right, Fuel line/needle valve blocked, or there's air leaking in somewhere (fuel line, around the carb, etc.). Try adjusting/replacing things one at a time until it improves.

Good news! Some fiddling around with the needle valve did the trick! Thanks a lot for the advice!