Hello everyone, I'm the newest guy (for the moment) to this fantastic sport! I purchased a Superstar 40 about a month ago and have VERY dated electronics in it. I have a Magnum GP 40 size motor in it. My question, or rather issue, is this: When I first start it, with the plug lighter still on top, I can successfully trim the motor to where it is running top speed very clean. But, only seconds after I take off the plug lighter the motor stops. Am I starving the motor? If so, then why does it run so well with the lighter on? I have a brand new plug in it. Thanx for any help, guys!!!!!!!!!!

Generally, if the motor stops when you remove the ignitor, it indicates the plug is bad. It can't hold the heat from one stroke to the next. You may have ruined the plug by running too lean. If you have another plug, you could try that. Open the needle another half turn, it never hurts to be too rich.

Tom

Thank you, Tom. I'll try to run a little "rich" with my next glow plug. Will running too lean ruin a glow plug? Because this new one is but a few weeks old. I guess learn as you go!

A couple of things to keep in mind. As Tom mentioned, a lean mixture will ruin a plug. Also, new plugs can be, and sometimes are bad. Most times the seal between the center element and the body of the plug leaks. A general rule of thumb that I follow is to not run up/tune your engine with the glo ignitor on the plug. Start the engine, warm it up a little, pull the glo clip off and take it from there_bob

Bob's right. You should remove the plug igniter prior to adjusting the engine.

Another important consideration; not only can you ruin a plug by running too lean, but you can also destroy your engine by running it lean. I've seen engines ruined by one lean flight. (Loss of compression, won't hold a setting.)

If you tune the engine to peak rpm, ALWAYS richen at least 300 - 400 rpm.
Dennis-

If your engine runs fine with the glow driver attached and dies as soon as you pull it off, it probably means your are TOO RICH on your high end needle setting.

Since you can start your engine with the glow driver it means you do not have a break in the glow plug element continuity. It is possible the element is contaminated but unlikely.

Yes, you can "fry" a plug if you keep a glow driver attached while running the engine at full throttle or if you experience a lean run.

If you decide to replace your plug, try an OS 3 plug. It'll last you a long time.

Thanx for the help guys. This is really cool. . .

Ahhhh, another satisfied RCU customer