Still running rich

[bikerboyriley1]

Hey so i have a 350 rhs heads and big cam, single plane intake, 670 holley street avenger..



So pretty much my truck smells of gas pretty bad, i rejeted carb (smaller) and still am gettin that smell. I know 2 of my spark plug wires arnt in great shape ( burnt) so it may not be firing conssitently.. also my other idea was maybe its the single plane intake ?... Any suggestions??

[oncearacer52]

Where are your idle mixture screws adjusted to? At what point do you think you are rich? Try taking out a spark plug and clean it up good and reinstall it. Then start the truck and let it IDLE ONLY for a couple of minutes and recheck the plug. If it gets black then close your idle mixture screws one quarter turn and do it again. Once you get the plugs clean at idle about all you can do next with that carb is change jets until it leans out.

You are right about the single plane in- take it will tend to give you, not necessarly a richer mixture but, a less atomized mixture. Personally for a street motor I would run a dual plane intake. You more than likely have a very low vacuum situation at idle also so that carb may never work thru the whole rpm range.

[Scotty_S-15]

I'll second that about the dual plane intake. Also, with a "big" cam, and reduced idle vacuum, are you sure you're in the idle circuit? Do the idle mixture screws make a difference? If little or no difference, you need to get the throttle plates shut more to get into the idle circuit. Some high-end carbs have a compensate for this, or, drilling the primary throttle plates can do the job. But, gotta make sure that's the problem before butchering up the nice carb. http://www.s10v8.com/images/smilies/icon_wink.gif

.......... But first, fix the plug wires! http://www.s10v8.com/images/smilies/icon_smile.gif

[soopertruper]

The secondaries on that carb have a screw to open the butterflies underneath.You shouldn't have to drill any holes. buy a book on tuning holley's. Its just nice to know what everyone is talking about. Are your float levels set right? What are the specs on your cam? I have an AFR gauge and with a burnt plug wire the guage was reading 12.5, fixed the wire, and it jumped up to 13.7. Don't even bother tuning until you fix the wires.

[chris1972]

http://www.carcraft.com/howto/ccrp_0507_carb_tuning_tips_tricks/carb_tuning_tips.html try this web sight .http://www.moparmusclemagazine.com/tipstricks/mopp_0504_tune/..and this on too hope this help ..i don't think it because the plate are open too fare ..

[bikerboyriley1]

Yah i was thinking that the single plane would be less fuel atomization so i was thinking i would put on a phenolic carb spacer maybe an inch tall