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Senior Charter Member
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Discussion Starter · #1 ·
I checked my plugs today and found the second plug from the front on each side to be much whiter than the rest of the plugs (the others were goldish brown).

Should I be looking for anything special? Seems to be running fine otherwise. The plugs now have ~ 1000 miles on them.

Thanks
 

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It sounds like mormal manifold distribution limitations. If it runs fine, to be safe go up one jet size. If it's EFI don't worry about it.
 

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Discussion Starter · #3 ·
Sorry...I should have given details of my setup. I was in a hurry when I posted...

I have a Roush 402 with a Holley 770 Street Avenger.

Thanks.
 

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FFCobra Fanatic
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12,975 Posts
What intake? At best you end up jetting for the average of all cylinders so it may end up being a slightly different afr for each cylinder.
Other possible cause's could be a vacum leak near front on engine causeing a too lean at the front cylinders.
 

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Discussion Starter · #5 ·
HindSight

Victor Junior High rise Single plane intake. The cylinders on either side of the light coloured plugs look OK. I'm probably just being to picky


Thanks
 

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FFCobra Fanatic
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Usually it would be #1+#5 that would be slightly leaner compared to #2=#6 like your seeing. You can check vacum to see if a leaks present but haveing some cylinders run "slightly"leaner then others is not uncommon. Reason some manifolds and carbs used staggered jetting to compensate for manifold design. Could'nt know for sure unlees each cylinder was watched with egt sensor or afr meter seperatly from the others.
 

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Discussion Starter · #7 ·
Thanks

You time is always appreciated.
 
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