Fine Wire Plug Repair?

[artrose]

I have some Champion fine wire plugs that don't exhibit any outward trouble signs. Engine starts easy, doesn't miss, can't tell any performance loss, and they look good visually. Question: After some minor cleaning I did a resistance check (repeatly) and confirmed some that read in excess of 9000 ohms. Replace? Keep running them? Is there a place to buy rebuild parts for the internals? Any suggestions? These plugs are very expensive and I'd like to save some money. Are the internal (removeable) resistors the same value for massives and fine wires? Are the resistors available for a plug rebuild? What is the consequence of exchanging the high resistance (bad) resistor from the fine wire plug with a good resistor from a massive? Anyone tried doing this?

 

[artrose]

Moderator.... Should I give up trying to get this post kicked up to todays posts so I might learn if there's anyone who has had any experience, or suggestions about replacing the resistors in a spark plug?

 

[flyboy1963]

don't give up!

Art, good questions, perhaps most of the A&P types on here are at work?
( there, just kicked it up again for ya!)

if you want some armchair opinions;
I think to accomplish the repair you suggest, you'd need to own the Champion/autolite/Tempest production fixtures!
You might want to verify the plugs' performance in a test cell, where the actual spark can be assessed under pressure. It's possible the 9000 ohm reading is irrelevant....as evidenced by their 'normal' performance.

just my $.02, (not worth a plugged nickel).

 

[Larco]

Try this number, 864-640-0680. It is the number for the Champion plug tech rep. At least it worked for me and he was very nice and full of good info. Larry

 

[BCP Boys]

I'm not trying to be a smart ___ but if things are normal why are you considering the expense and trouble of possible rebuild? That usually happens after some issues are present correct?

Also, another comment. I'm running the fine wire in my -7 and ran the fine wire in my Twin Cessna but at Oshkosh this year I saw the Tempest internals and was very impressed at the comparison. If you are not familiar with the difference it may be worth your time to do some research on Tempest plugs if you want to replace/rebuilt.

 

[David Paule]

I had what I thought was a sticky valve in one cylinder in my Continental O-470 engine. The AI suggested I check the plug resistances. I checked all the plugs. The resistances were all over the place, from low hundreds to above 100k. The plugs in the "bad" cylinder were on the low side of that range.

I replaced the ones in the bad cylinder and the problem went away.

I later learned that measuring the resistance at room temperature isn't worth much.

Having a six-cylinder EGT was worth a lot, and that I recommend. Also, if the engine runs fine then the plugs are probably good. If it doesn't, then plugs are a relatively cheap diagnostic -- you do have some spares, right?

Dave

 

[Mike S]

Moderator.... Should I give up trying to get this post kicked up to todays posts so I might learn if there's anyone who has had any experience, or suggestions about replacing the resistors in a spark plug?

No, you should not give up.

But when you just re-post the exact same message, it looks like you did a double post/hit enter twice etc.

May I suggest you try "Bump to the top" or some other similar phrase that will bring the thread forward, and not confuse poor moderators brain

 

[BillL]

I just went to the Champion website and watched the 9 minute video. They say use a pressure firing test and are very specific that a VOM resistance measurement is not accurate. It is a good video.