How Can I Prevent Fouled Spark Plugs When Running at Idle for a long time?

[KM7]

How can I prevent fouled spark plugs when running at idle for a long time?

Better yet what can I do to clean the plugs without removing them?

I've been having a great time cruising in my local harbor, looking at the Christmas lights on the houses along the harbor.

The problem is, when running at only idle for a long time, the spark plugs tend to get fouled. I have not pulled them, but I can feel a difference. The Idle gets a little rough. To smooth it out, I'd have to speed up just a little bit. But, because there are a lot of other boats in the narrow channel that are also going very slow, I can't speed up.

I know I could run at a high RPM before I leave the dock, but that would only be in neutral. With no load on the motor. I'm not sure that even that would improve things.

Any thoughts?

I did fuel up with a higher octane 91 VS what I usually use, which is 89.
Will that help?

I could add some fuel additive that is usually for injectors, but this is a carburated, not injected motor (Ford 5.8: V8 Holly 4 barrel)

What else would you suggest?

Thanks

 

[redneck joe]

Im no expert but that sounds like a carb adjustment problem.

 

[Bondo]

Im no expert but that sounds like a carb adjustment problem.

Ayuh,..... The spark plugs should run, coffee, 'n cream brown, over the entire rpm range,....

 

[Scott Danforth]

what color are the plugs? white, tan, black?

is it fuel fouling or oil fouling?

is it running too cold and you are getting condensation?

are you suffering from reversion?

you should be able to idle for perpetuity unless either your carb is set too rich, your ignition system is not up to task, or you have serious blow-by

being a carbed 351, my guess is you have points ignition. when was the last time you serviced the points? if your dwell is off, your timing is off. if your dwell is off, you can start to have insufficient spark energy, leading to fuel fouling

what is your compression numbers on all 8 cylinders. do not say "good" what is the actual PSI compression on all 8 cylinders?

anything over 87 octane is a waste of money

 

[racerone]

Agree with the above post.-----Assuming it is plug fouling is a mistake.

 

[cyclops222]

Arm chair boaters frustrated by conditions that at are normal.
I will not pay anyone to set my boat up correctly.
Oh well.