I checked the outboards this morning and they are closed.I also sprayed around the intake and nothing changed.I am so frustrated with this. I agree that it seems like a vac leak but ??? Just doesn't make sense. I may have a super bee for sale

Dist phasing is the last thing you need to worry about, most of your issue seems to point to a vacuum condition or fuel surge, disconnect the end carbs linkage to confirm the throttle blades are indeed fully closed, leave the linkage off until you have the idle sorted out, confirm that your fuel level is proper height in each carb, timing wise I'd start with 10 degrees BTDC, attach a vacuum gauge to the manifold port, at idle, motor fully warmed, choke fully off, idle in the 800 range (try and keep idle as low as possible thru out the set up procedure), turn in (one at a time) the center carbs fuel/air idle screws, turning out one screw at a time to achieve the highest vacuum rating you can achieve under the your current conditions, after you've set up the center carb initially, move to the front carb, blocking the outer air bleed located in the carbs throat with your finger tip (there's an outer bleed port in each venturi/throat/barrel) see how that effects idle, if the idle picks up that end carb bleed is lean, if the idle drops, it's rich, turn the base screw in/out as needed until there's very little to no noticeable idle change, do each side one at a time on the front carb, even after setting the idle screws, be it on any of the carbs, go thru the idle/fuel/air adjusting ritual 2-3 times just to balance off your adjustments, after you've adjusted the front carb, if you don't have a tool for accessing the rear fuel/air idle screws, remove the carb and swap it with the front one, with the rear carb now on the front of the motor, set the air/fuel idle screws up using the air bleed block off method, the nonsense of "X" amount of turns out/in only applies to an initial start up, you need to tailor the air/fuel idle circuits to your engines characteristics, if this doesn't establish a better running/idle condition, and your in the same boat with an erratic idle, then you need to look for a vacuum leak, even to the extent of pulling the manifold, new or not it could have an undetectable crack.

I'll assume you tried running in both center carb fuel/air idle screws and the motor stalled/sputtered to confirm the freshly installed PV/gasket is not leaking


Mike

All good responses. I had a similar issue with mine. It would especially show a high idle after I opened the outboard carbs. I found my issue to be the butterflies in the outboard carbs were sticking, just before they were completely closed. I had to push on the throttle shaft of the outboards in order to get the idle where it needed to be. I fixed mine by gently filing the throttle blade into a knife so it would not hang up. It took a long time to find this, so don't cross it off your list until it's checked. I puppied the car home with a high idle, got out and pushed on the secondaries to find the issue. I was told (as mentioned earlier in this thread) that tightening the carbs to the intake too tightly can warp the carb body. I now use a screw driver/ratchet in order to put them on nice and loose. No problems since.

By all means, it could be a vacuum leak as well. When you installed the valley pan, did you use permatex or other gasket maker where the front of the valley pan meets the bottom...it is the area just after the outside bolt of the valley pan on all four sides. If not, it can leak on the bottom side. Good luck.

How do you have the floats set? Do you get a trickle or a stream of fuel out of them? Verify the linkage is not hanging up anywhere.

Pull the carbs off and ensure that your throttle blades are not hanging up on the gaskets or manifold. Make sure your air bleeds are clean and clear of contaminants. Check inside the float bowls for contaminants.

Pull the intake and use the Hughes Engines intake sealing wax string or equivelent to verify fitment.

Do you have MSD? Are you using a standard dial back timing light or an MSD timing light?

it might be leaking on the underside. what about punching a very small hole in the valley pan at each group of ports (4 holes) & shoot some starting fluid in there with the thin red straw. you could solder the holes closed later when done

Fresh engine,,,,,camshaft degree, at minimum camshaft and crankshaft marks lined up? Long shot just asking.

Converted to electronic ignition,,,,before problem or after problem raised its head? In other words was electronic ignitiin installed after to possibly fix problem. If before problem,,,,perhaps the issue lies with unit or its installation.

Spark plug wiring firing order all in order?

Extreme exhaust odor Indicates possible misfiring of cylinders,,,,or overly rich fuel mixture.

Fuel line system in order from tank all the way to carb?. Not 3 year old fuel from car sitting for long period of time awaiting new engine.

Which carb to intake gasket are you using ? If you are using the thin black gasket in this picture,pitch it and use the O.E.M gasket.Even if it is not the problem,use the O.E.M. gasket.

I just checked all float levels,just trickling out sight hole. I am using the thicker Holley base gaskets. Electronic ignition was installed prior to start up. Yes timing marks were lined up and firing order is correct. Linkage rods and butterflies are good.After checking all of this,problem still exists. Timing seems to best at 20 btdc using a standard dial back light. This is a complete resto fuel system is new. Running mixture screws in causes stall out.Covering vent tube causes stall out. Cupping my hand over air horn picks up rpm which leads me back to a vac leak as most of you said.Thanks again to everyone that is trying to help me on this. Looks like I'm pulling the intake off again and see what's going on. You guys are great. I'll let you know.

Not for the faint of heart. You are on your own whether to consider following suggestion. However I have successfully done this in the past.

Disconnect fan and alt belt.

Using garden hose with no nozzle on it and engine NOT hot, warm ok.

Place and hold end of hose on radiator end of turkey pan

Have your helper start the engine.

Run for a minute to allow to settle down as much as possible. Note engine rhythm.

Turn on water to a modest stream under and over intake and all possible vacuum leak possibilities. A couple of minutes should prove sufficient. Fan was disconnected so as not to spray water everywhere.

Engine rhythm change at all as it will if water is sucked into engine? Hopefully not enough to cause hydrolock.


Also as ignition change was added to the equation, consider installation of prior system to eliminate new ignition as cause of problem.

"This is a fresh engine and first time running."





Are the rings seated yet?

what kind of piston rings did you use?

plain iron rings seat quick but some of the other kinds take longer.

synthetic oil might slow down the wear in process as well. (low vacuum/low signal at carbs)

You sure you dont wanna get some starting fluid under there first? EDIT I'd lift the front/rear valley pan end(s) & shoot some starting fluid in that way & see if it changes (& cap the PCV port).

Your hand over the carb as the engine idle picked up tells me everything. It's sucking air from somewhere.

but will add, Or it may just be lean.

To the OP,
Have you verified that the mechanical advance is not coming in to early ??
You may have more than 1 issue contributing to the problem.

what year?

So is the issue resolved? What did you find?