Fouled plugs at idle speeds
 

It appears that fouling out my plugs seems to now be a regular occurance lately. Probably has to do with now that I have my boat at the yacht club, I have a 15 minute idle down the river before I get to the open waters.
I have already bumped the heat up one range to try and resolve the issue, but no luck. I am running NGK plugs BKR5ES11. I have no soot on my transom. I worked out the richness issues last season and I should have the right jets in there now, but last season I didn't do nearly as much idleing.
My carbs are fairly new Holly's 750 cfm 4160 with 4150 secondary blocks (so I can change out jets).
Any suggestions?
I am thinking there is a idle mixture adjustment that needs to be done, but not sure exactly where that is? How much to move it? And what direction to move it?

Re: Fouled plugs at idle speeds
 

best way to set idle mixture is with a vacuum gauge, here is one link on how to http://www.chevyhiperformance.com/howto/45638/

Re: Fouled plugs at idle speeds
 

Do you have a big cam in the motor? If so, take the flame arrestor off and look down into the primary. If you see fuel dripping out of the booster you may need a different power valve.

Re: Fouled plugs at idle speeds
 

The cam is fairly big... the largest roller cam that my builder was comfortable installing with wet exhaust. I will check that out and see if there is fuel drizzling out.
We did adjust the mixture with a vacuum guage initially last year. But it is an extremely touchy situation... the guage bounces a lot, etc. And at this point I was thinking I would just back off the screw a little at a time, but I don't know which screw.. I'll check that web page.

Re: Fouled plugs at idle speeds
 

Try and get best average vacuum reading at idle, power valves should be about half of that reading.

I ended up with 2.5 power valves in order to get them to stay closed at idle.

Re: Fouled plugs at idle speeds
 

Good article.

Re: Fouled plugs at idle speeds
 

Found another good one on power valves :D

http://www.chevyhiperformance.com/te...ems/index.html

and this http://www.mortec.com/carbtip1.htm