ok-getting interf only with engine running-this is the stock ch ignition .no plug shieled cover-this is the only thing missing.my other 2 gas planes are fine-did everything the same as the other 2 but still have interf. any help will be appreciated.

Since you don't have the Bosch Cap make sure you have the ground line (line that runs to spark cover) grounded properly.

Try molding a piece of aluminum foil around the spark plug boot and spark plug base. Secure with plastic tye wraps. This may fix your problem.

Ken

I'm a believer in the Bosch cap - CH Ignitions will sell you the lead which you can solder in yourself, or they will do the work for you.

If you do switch to the Bosch cap (and this is highly recommended) for goodness sakes put a band clamp around the cap end to hold it tight to the plug base. Otherwise you may get some interesting spark generated interference.

Don't ask me how I found this out.

rcairmike,
Make sure your ground wire is connected to the engine as close to the plug as can be. Also, make sure your connection is good an strong. crimping alone may not be enough.

Is that your CAP you're having ignition interference with? By the way, I owe you change for those glow plugs last Sat. You gave me $5 more than I thought.

JJ