Plugs keep foiling up

[kennyhbh]

Hi guys. change the plugs still having the problems. gap 55 . running msd. change out the cap and rotor . swap in a different 6al msd box . wont hold a idle have to keep pumping pedal keep it running, at higher rpm i can here it miss fire. side pipes are black carbon. also the plugs that i took out weren't filled with carbon.

[bobcowan]

Originally Posted by kennyhbh

Hi guys. change the plugs still having the problems. gap 55 . running msd. change out the cap and rotor . swap in a different 6al msd box . wont hold a idle have to keep pumping pedal keep it running, at higher rpm i can here it miss fire. side pipes are black carbon. also the plugs that i took out weren't filled with carbon.

Gap is too big. Bring it down to about .035" or so.

So probably not too rich, and probably not oil fouled.

But you might consider going one heat range colder if they foul out that quickly with a smaller gap.

You could also consider cutting the ground electrode back like in a racing plug.

[Gaz64]

Originally Posted by kennyhbh

Hi guys. change the plugs still having the problems. gap 55 . running msd. change out the cap and rotor . swap in a different 6al msd box .
wont hold a idle have to keep pumping pedal keep it running, at higher rpm i can here it miss fire.
side pipes are black carbon. also the plugs that i took out weren't filled with carbon.

What carburettor?

Sounds like one or more blocked idle air bleeds.

Some pics would be nice.

As Bob has said, plug gaps are too big.

Never heard of your plugs either.

[kennyhbh]

We're are these idle air bleeds.

[Gaz64]

What carb do you have Kenny?

[kennyhbh]

Hi , Holley 770 street adventure .

[jhv48]

Before you start messing with colder/warmer plugs, determine whether the plugs are oil fouled or fuel fouled.

Different solutions to each of these. Plugs will appear black and could be damp and smell like gas if fuel fouled. Black and oily will be more problematic to solve.

[Gaz64]

Originally Posted by jhv48

Before you start messing with colder/warmer plugs, determine whether the plugs are oil fouled or fuel fouled.

Different solutions to each of these. Plugs will appear black and could be damp and smell like gas if fuel fouled. Black and oily will be more problematic to solve.

Correct.

Do not try to correct the condition you have with a hotter heat range spark plug.

For a street car, one range colder than factory spec is generally enough.

What camshaft specs have you got?

Give the idle air bleeds a shot of carb cleaner first and reassess.

http://members.tccoa.com/392bird/airbleeds.jpg