Champion J6J or J6C

[drifter]

Is the Champion 823 a replacement for the Champion J6J or the J6C?
Thanks,
Drifter

[twostroke]

Yes.

I say "pardon me" a lot. I had a 20H, then raced open mod sleds.

[nj-boatbuilder57]

I believe it’s like a J6C. 823 & j6C have lateral (grounded) electrodes that end at the far edge of the center electrode.

By contrast, the J6J (discontinued) has a lateral that ends at the center point of the center electrode.

Does it matter? Just for grins, I filed a J6C into a J6J, and noticed no difference in performance whatsoever.

[Tubs]

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

• This reply was modified 6 years, 5 months ago by Tubs.
• This reply was modified 4 years, 2 months ago by Tubs.

[nj-boatbuilder57]

In fairness, I didn’t state what engine I did the "J" mod in. It was a 15HP Evinrude with all-new electronics. I could see how a smaller engine with weak electronics could have a different result.

[drifter]

Seems that I remember racers filing the electrode back.

[Pete]

quote Drifter:

Seems that I remember racers filing the electrode back.

That is true, cut back electrode proved better. Ex on my 1973 Merc 25ss it came with polar gap Champ L78V plugs, for my racing (back in the 70’s) they were a problem. Couldn’t read for combustion conditions and the flooded a lot. Best plug was determined by many racers to be a Champ L61Y (NLA), projecting nose with factory cut back ground electrode. I saved 10 and still use them on the same engine at AOMCI meets great plug even over NGK BP8HN-10 supposed equivalent which is not cut back. No fouling, no flooding, ran great. Also could retard the ignition some with the deep projecting center electrode.

[foot_doctor]

Remember Tetraethyl Lead? It was the additive used to improve the octain of our fuels many yeas ago. One of the consequences of it’s use was the precipitation of lead balls on the spark plug electodes. If enough of them gathered, they shorted the gap. No Spark. OMC and Champion Spark Plug company did companion research on the malady and came up with the cut back ground electrode that provided 50% less area for the Lead Balls to congregate on, and allowed the incoming fuel charge to sweep the more exposed gap clean with each piston stroke. The J-gap plugs were produced in a limited number of heat ranges, and were specifically designed for use in 2-stroke engines. They were not meant to provide any performance advantage. The Y-gap plugs referred to earlier were originated for the Chevrolets 283 cu. in. engines and were L12Y. They present some unique advantages.. They ran hotter at slow speeds, and cooler at high speeds. We were fortunate that Champion made the colder plugs with the Y-gaps for our use, as they were proveably faster in some engines if we were able to keep the ground electrodes from being closed by contact with the piston domes. This stuff is fun, isn’t it? R.T.

[garry-in-michigan]

Some racing motors were affected by which way the side electrode faced when the plug was tightened. . . 😎

[Pete]

quote Garry in Tampa:

Some racing motors were affected by which way the side electrode faced when the plug was tightened. . . 😎

Garry right on. I would index the plugs on the race engines. Would point the ground electrode as close to the center of the intake ports as reasonable. Usually in a range of 25 degrees up and down from center intake port. Wanted not to shadow the fuel charge with the electrode pointing toward the exhaust side.

Foot Doc – yes it was and is fun. I read about plug indexing in a performance cycle mag back in the early 70’s and did it with the race engines then and now. With the L61Y I would also open the gap as wide as possible (like 0.065") and not strike piston , could do that with the CD ignition with a lot of fire power in the system. Also tried cutting the ground electrode off so only a vertical electrode piece remained so the spark was completely to the side. Ran good no loss in performance, but a bit more difficult to start, so for racing wanted start reliability and never used the side spark at the races.

[Author]

Posts