[Whaler]

Hello David

You are going through exactly what I am with my carb/engine now. Whether u were following it at all, there are good tips on carb tuning posted on a thread I started asking about total CFM for the dual 4 crowd

Anyhow I have some questions for you.

1) Is your carb the Holley 850 with man or vac secondaries?
2) Doe it have a choke- manual or otherwise?
3)What is your base idle set at ( Intitial )
4)What heads and cam...is it cammy?
5)What fuel? octane wise?

6)If you have the MSD, what springs did you choose for your advance curve...this will help solve the 4000rpm question

I too suffer a pop or 2 on initial startup. I have a manual choke thats wired wide open on my Holley 850. After a warm up I have idle at 900-1000 with 10 inches vac. when I shut it off it sometimes stops cleanly and other times it has a slight run on ( you know 2-3 more sputters) And mine too smells like fuel.
My initial is set at 14 as a start point and I don't know to go up or down with the slight run on as it is. I hear that never less than 10 and never more than 20 is a good ROT

Is yours a new problem? Did the car run well before? What had changed?

A stumble could be lean or delivery problems.
I take it you have fooled with the idle air/mixture screws? The place to start on those is 1.5 turns out from close on each corner ( if you have 4). Out richens and in leans
Adjust these out or in, until the car just falters.
Also adjust the screws equally and if you have one, use a vacuum gage, and adjust for peak vacuum. This adjustment some times changes your idle RPM and that may have to be reset after.

Hows the float bowl level? The sight plugs should either just have fuel visible at the edge or starting to TRICKLE out.Ahigh level here can cause flooding and richness in the idle if it even starts.

There are good tips in the links I had included in that earlier post.

Tim