I need some expert help with my carb setup. First, here are the specs:

355, Edelbrock RPM Heads
Edelbrock 1806 650 cfm Carb
Edelbrock RPM manifold
CC 268H Cam
LT Headers, 2.5 exhaust
2400 stall


To get it running the best, I had to lean it down 2 stages - stock was way too rich and had blk smoke out tailpipe. Here is what I have things set at:
Primary: .095 Jet, .070x.052 Rod
Pink spring, lowest hole on pump (weakest)

I've had some bad hesitation off of the line. To avoid it falling on its face I have to ever so sloooowlly feather the throttle to get it moving. Today, I put in new plugs and rechecked timing and idle mixture. Here is what the plugs looked like after 2000 miles (replaced today). They look pretty fouled to me:

Old Plugs (http://www.mikelsall.com/gallery/listpics.asp?a=show&ID=13411)

Here is what the plugs look like after 25 miles around town. These were pulled after I pulled into the garage under normal driving for this car - it's a cruizer and spends 90% of the time below 3000 rpm.

New Plug 1 (http://www.mikelsall.com/gallery/listpics.asp?a=show&ID=13409)
New Plug 2 (http://www.mikelsall.com/gallery/listpics.asp?a=show&ID=13410)


They still look rich to me. You're supposed to be looking at the ring land, right? If still too rich, is this carb just too big for my combo (I can't go any lower in jetting)? This bog has become so bad I can't even drive the car anymore. I need some drastic help....I don't know where to go. I hope this is an easy one to fix - even if that means purchasing another carb!

Thanks.

Too sooty.

What's your idle quality like ? That should be the first thing you adjust. Then tune for WFO. If you got to, go to a THICKER rod. Maybe more taper at the bottom. This is more like how a QJet is tuned....

You MIGHT need a smaller primary jet. I'm far from a Eddy carb tuner. I just finally learned how to get a QJet 'right' :crazy:

http://www.edelbrock.com/automotive_new/mc/carbs_acc/pdf/carb_owners_manual.pdf

And use this to help you with the rest (the SEARCH function is your friend)
http://www.nastyz28.com/forum/showthread.php?t=47140&highlight=edelbrock+carb+tuning

Idle is good, no problems there. It's just right off of idle where it hits a bog. I can also feel it when moving/coasting and touching the gas pedal again.

I've gone as far as I can go with leaning this thing out. It's current combination has the smallest openings for both power/cruise mode.

Thanks for the links too, but trust me...I wouldn't ask for help without attempting to research and resolve myself. I've seen that post and can almost recite that dang manual verbatim. Thanks again for the help though, rs.

I'm really starting to think that the carb is just too big for my combo. But I'd like some other opinions before I go out and spend some $$$ for something I might not need. I'm also assuming the secondaries are not causing the fouled plugs (stock size) cause I'm hardly ever at full throttle.

Can a carb be too big? It just seems to still be rich even when I go all the way lean (#20 on the chart p18 ). What gives?

whats your fuel pressure?? Over 5.5 psi the carb will run rich, try to flood out, etc.. Install an adjust fuel reg and turn pressure down to 5.0 to 5.5 psi max.. ( I run mine at 5.25)

The bog is mostly due to the float settings and pump arm..

Check floats and set if needed.. 7/16" at rest, 15/16" to 1" drop

Move the pump arm back to the TOP hole.

Set idle mixture screws using a vac gauge.. Turn screws 1 at a time till you get the highest vac.

Ok, now lets think for a min.. Your probs is at lower speeds.. Like you said, you stay below 3K most of the times..

The rods has a tip end thats one size, then a fatter end... Tooling along the rod is down in the jet, the fattest part of rod (your .070" size) and as you throttle up, the step up spring lifts the rod out of jet so jus the tip is sticking in jet (your .052" size)

Right now you want to tune the cruze side not the power side..

The pink step up spring is putting you into the power mode (small tip of rod) sooner.. (As you press the throttle, you get to 7" of vac, before you do 5".. I say put the orange 5" HG spring back in.

Keep your smaller .095 jets in

If still too rich.. Try a rod with a .075 fat end.. Like the 075 x 047

If thats still too rich, try 092 jets, but I don't think you'll have to go down that far.

600-650 is perfect for 'most' 350's.....heck, even some smaller big blocks.

I think its a tuning or fuel issue as mentioned. That carb is NOT too big.....

Then again, your 'stumble' might be a LACK of fuel too.....at least in transition.....might wanna see what going from WFO to idle is like WHILE driving....

Thanks guys. That all makes sense. I'm also wondering if it's possible my choke is not fully opening up. I'm guessing this could also cause a rich mixture at all times. I know it's something simple.

I'll try what is suggested and let everyone know how it works. Thanks.

I ran an Edelbrock 600 for a while and never could get it just right. I think that between getting the fuel pressure down to about 5.5 psi and getting the choke adjusted properly, you should be able to resolve the problems. In my case, the choke would never come off completely and always ran rich. I gave up and put a Holley on it because I have run them for years and know how to tune them. Good luck.

Bingo Baby! OK, regardless of how embarrasing this is I need to reveal the solution in case someone else comes across the same thing.

This winter I dismantled the carb to perform a thorough cleaning. When I put it back together, I made a tiny mistake in reconnecting the choke linkage that runs across the carb from the choke to the throttle linkage.

In this picture (http://www.mikelsall.com/gallery/listpics.asp?a=show&ID=13412), I marked an arrow what I'm referring to. I had the finger on the cam piece on top of the hooked finger. With it on top, the choke never fully opened up because of the linkage down below stopping it after it opened only about 3/16 of an inch. So my choke never really opened up and I drove for a loooong time like that!

Besides being irritaded with myself, it would have been better if it only fit one way. It's a hard thing to catch and I went threw a nightmare to get it figured out. Anyways, the thing runs like a champ now. Pins you back in the seat with the slightest pedal from a stop - I thought it ran good before!

So back to the drawing board to tune it up. At least I know I have a workable piece now. I'm also hoping that this will fix my horrible 9 mpg issue.

Thanks everyone.