#8 plug keeps fouling,why?

It could be timing because of more resistance at the plug with more timing combined with a cold plug, but I bet you cured it with the hotter plugs. A 7 is pretty cold for a streetcar. NGK recommends a 5 for stock replacement. I will guess that the Al heads help the plug cool better too (though I don't know this as a fact).

Can you post a picture of the fouled plug?

 

Adam i hope i cured it,we`ll see in the next couple of days if she fouls again,i will post a pic of #8 and from another cylinder to see the difference.

Thanks

 

Here is the best pics i can get,you`ll know right away which is #8

 

this too

 

yes they both are but the #8 is worse,what can cause it?bad carb adjustment?cold plugs?

Thanks

 

Both of those plugs are Rich....... number 8 is VERY rich! The porclin shouldn't be that dark like that (very light brown is nice). It looks to me like it's been running really rich for a while.

If you haven't been running the car hard, your deffenatly running to much primary jet and that's what's killing the plug.

 

well i went back down to what came in the 800 dp which are 71`s,i had put in 73`s,i dont normally run the car hard.

Thanks

 

That will help,

After putting some time on it, pull them all (keeping them numbered so you know where they came from). This will give you an idea what your jetting is like to each cylinder and if you should be stagering your jets. However, If your not running your car hard, all you have to play with are the primary jets. I feel confident saying they fouled because you were running overly rich. Chances are, you could even drop to a 70 or so......... Just keep an eye on the plugs, they tell the story.

 

I`ll see how she runs in the next few days,i`ll keep you posted:TU:

 

You are definately running WAY too rich there. What you are doing is gas fouling the plug. Alot of times, once they gas foul, even cleaning them won't bring them back.
Lean that thing out!
It could be being caused by an interanal carb leak too. Is the car sometimes hard to start when warm after sitting for awhile? Jim Burek

 

Jim,sometimes when hot i have to crank it alittle for it to start over,you think my carb may be leaking?internal leak or what?

Thanks

 

Wouldn't a carb leak affect all the spark plugs color.

 

Switching from the TA to B4B intake would give the carb a lot better vacuum signal and the resultant extra fuel, couldn't it? I should add that would make you have to jet down a fair amount.

 

Absolutely, Holley carbs a re known for internal leaks due to metering block warpage. Qj's as well due to other reasons.
I did not catch what carb you have on it , I was assuming a holley.
But no doubt, you are way too rich due to a leak or jetting. Jim Burek

 

Hey George,

It just hit me.... what size powervalve are you running? If your running a 6.5, it's very possible when your leaning on it a bit, it's opening and dumping to much fuel in causing your plugs to foul. I personally use 3.5...... just something else you may want to check.

 

I had the same problem when I ran a B4B on my '70 GS, checked all the things that has been posted here, The only way I figured out how to "fix it" was by adding a 1-inch spacer under the carb. Drove the car many miles after that & never had a problem again!! Good luck.

 

I got a small power valve already,its a 3.5.

Thanks

 

I dunno George.. thats looks pretty bad to me.
I'd guess your engine has about 1 week left before she blows.
Maybe now would be a good time to trade cars with me.
Even up swap! My little 300 still has the same plugs in it from last year, and I'm sure they all still look great. :Smarty: ou:
:laugh:

You knew I'd be here sooner or later didn't you? Who knows.... if I keep trying.. maybe I'll catch you in the right mood one of these days!
A guy can dream can't he? p

:beer

 

lololol:TU:

 

UPDATE:


Well guys i had installed the hotter running plugs and i told you i`d get back with the outcome,still #8 plug fouled and this time i pulled it out it was wet as in gas wet not oil and the car has been sitting for a day or so not being fired up,at this point i really dont know what causes this problem?next thing to do is a leak down test i guesso No:

Thanks