Hey Guys I did my own Homelite conversion and it runs great I tach it at 7800 with a 17-8 wood scimiter prop. I have been having some radio interferance and it cause a bad crash but was able to join the 2 halves of the fuse and fly again with the same problem only this time just the landing gear got broken. I have the radio at lease 3 feet away from the motor and the throttle about 2 feet. I have flown it a few times and had no problems but before the big crash I had put this NGK BPMR7A plug in it and that is when the problem started. Does anyone know if the R stands for resister or is my pcm radio being shot down by someone.


I would appreciate any comments, also can a resister type plug loose it's resistance. I would really hate to loose this bird the next time I fly it so I am taking all the precautions I can cause it could also hurt someone on the flight line or else where.

This should help with the plug codes. Nutshell ir is a reistor type
http://www.ngksparkplugs.com/techinf...tnumberkey.pdf

FWIW Found this via : http://metal.duncanamps.com/links_info.php which is neat..

If you doubt the plug spend a few bucks and buy a new one.... heck of a lot less cost than your plane and time repairing it.

Take a real close look and verify you have no metal to metal contacts that may be vibrating. I may be over cautious be I choose not to use any metal clevises on control rods (if I did I'd probably CA them after adjustment. I had glictching while using a makeshift plane alum model stand (modifed walker), off the stand no glitching. A new wood stand is in the works.

that is the same plug i have been running for several years with no problems

Thanks Ken and Miken, I had my doughts about the plug but when I saw that it is of the resister type it tells me to look elsewhere so I guess I will be taken everything apart in search of the answer.

Check your high tension wire very carefully...look for tiny cracks...
Also get a Bosh Shielded Cap....if you can find one..
Can't remember where I got mine...

Whatever you do...don't fly it till you get it resolved....

Good Luck!
CrazyHerb

CA with a metal to metal contact is not very tolerant of vibration, might just want to touch a soldering iron on there instead. That is what I did on my big plane, threaded control rods where needed, which are also soldered. (after it was flown and trimmed!)