Ok

I have a Moloney 100 on a kit built Taube. I have pulled my hair out over a glitch problem. The plane has no problem while the engine is not runnig, but as soon as I get a few feet she starts glitching. I have checked just about everything I can think of and it still will glitch. It is a gas engine and has the old style magneto ignition. I think the only way to stop this is to change the ignition to cdi, but I hate to spend the extra $ if it is something else. Please help?

Have you checked to be sure you have a resistor type spark plug in it? Sounds like the symptom you would expect from a non resister plug.

It has the old type that came with it and it is around 20 years old I am sure because that is how long it has been out of production. I think you may have got the fix. I am not sure what size and type it may need. I have a Zonah 26. I will see if they are the same. Thanks!!! I will report.

The threads on the Champion RZ7C plug in the G26 are too long, the piston might hit the side electrode...The CM6 plug in the engine is not a resistor and there are no short resistor plugs..
A fix would be a shielded cap from C&H, DA, or 3W that fits the plug, but the mag might not be strong enough to fire a resistor plug, and the shielded caps have a built in resistor...
Or you might get by with a spacer under the resistor plug if the mag wire is long enough...
A CDI ignition would save much weight and would work, but the cost might be more than you want to pay....
You might try a new CM6 and aluminum foil around the plug and wire, all the way back to the mag coil...Secure it with some tie wraps...

RCIGN1, I can tell you know what you are talking about. The engine in not worth the $ money to put a new ignition on, so a plug or cap. I did try another cm-6 plug with the same luck. I called NGk. they make a resistor plug that is only 1 mm longer. It is the NGK cmr6a stock number 1223. if I have the room it should be fine if not I will add a 1mm shime and it should still be fine. I hope this fix's the problem. If not DA makes a cap that may work too. I will report. Thanks for all the info.

Go to www.sparkplugs.com, check out the differences between the CM6 and the CMR6...The thread is way longer on the bottom and the insulator is way longer on top...

NGK stated it was only 1mm longer in length. It would most likely work, but they would not recomend it. I think the plug is $3.19. might be a waste of time, but I will try it and hope[]

OK The plug stoped the problem, but this is the worst engine I have ever had. It is heavy, low power, and is hard to start and run smooth. I got it at a deal and hoped but. I should have know it was a bad one because they have not made it in years. replaceing it with a Zenoah 23 I have.

Thanks
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