spark plug advice?

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04-01-2011, 09:58 PM

#11

Griff

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Quote:

Originally Posted by lake speed

I have a 632 with dart 360 heads, dominator carb with 88"s in the front and a 6.5 pv and 95's in the rear.... i currently have a set of ngk -8 plugs in it but i am afraid that they are too cold. I used to run autolite ar3932 but they are hard to find around here. it has been so humid the the engine is fouling plugs and i think with a couple of jet changed and a hotter plug i should be fine. anybody have any reccomendations? does anyone elese run power valves or do you guys block them off?

If you are fouling plugs at idle, go up one heat range to a BR7FS. Jetting has nothing to do with fouling plugs at idle. You can try to lean out your idle mixture.

Quote:

Originally Posted by sleek1

What engines do you have? I have 500EFI's and was told to use NGK 5YR or NGK 5UR if long idles/no wake zones. Does this advice sound correct?

Those are too cold for a 500efi. They are NGK UR5's and are the same heat range as an AC R41T and have a slightly extended tip. The are the same heat range as the NGK 8's he running.
You should be running NGK BR6FS or an AC R43T. You could run the extended tip version AC R43TS as well.