Ok, i just got my FB all together and tried to start it for the first time yesterday.

It is a 12a with large raceports, intake and exhaust. It has RB headders, and the RB manifold. I currently have a 750 single with vac secondaries. Anyhow I cant get it do idle at all.

This is the steps I used, I have an electric fuel pump, turned it on and set the floats till just a bit of fuel trickled out on both bowls. The secondaries just have a meter plate in place so i didn't mess with any thing there. I also forgot to check the size of the primary jets, I think they were .75. Anyhow The jet screws I ran all the way in and took back out 1.5 turns.

That let me no where, with 5 turns out and idle set to 3k rpm it would idle but i dont want to keep it that high.

I'm thinking the 750 is just to large. Would I be better off getting a 600 and doing the steps again to see what I get or am I also doing something wrong?

 

750 CFM is way too large. Bigger is not always better. :-)

Also check for vacuum leaks. Vacuum leaks are the #1 cause of no idle/poor idle situations.

 

go down to 68 on the jets

 

I was thinking of changing the jets but no fuel comes out of the horns below 3k rpm.. I'm not sure what the problem is there.

 

Drop the jets, and remove the power valve, and replace with a power valve plug. This will help alot. Looking at your pic, the carb is turned backwards. The front of the Holley should be facing the drivers side. This may also be part of your problem?

 

^^^^^ choke stack should be closer to the alt. oooops Just like bad83 said.

 

Take that carb and give it to one of your V8 friends or eBay it. You will never get it set to run right no matter how many changes you make, short of changing the carb itself. What possesed you to buy a carb that big in the first place? I hope it wasn't advice from a so called 'rotorhead', lol.

 

Naa, I got it for $100 on ebay. I thought it was a deal...

As far as the carb being on backwards every setup like this I have ever saw was just like this, reason being if you turn the carb around the cables dont reach for throttle and choke.

I didn't try smaller jets or the power valve block-off thing.. I'm thinking of just going with a 600 CFM.

Right now I found a crack on my oil cooler so i need to take care of that first.

 

Check for vacuum leaks -everywhere.

That carb is way too big.

 

I have never seen a Holley mounted your way on a RB intake. Sorry for the big pic, but just wanted to show you that the carb is supposed to be mounted with the throttle linkage to the firewall. I don't know what adverse effects it would have, if any. I do know that the Nikki is mounted the same with the throttle linkage to the firewall, and the primary barrels of the carb going to the center iron. I would suggest turning the carb for a trial run anyway. As far as that 750 being to big, technicly yes. But eveyone told me that a 600 on a stockport would never work. I won't get the fuel mileage of a smaller carb, but the old girl screams to 7 grand, and still gets 15 mpg with me driving it.

 

Show me a good picture of how your throttle cable is hooked up please.

 

Ok, I got a 600 now. Now I need to know what size jets and power valve to use. And needle settings if you remember, also what meter plate for the secondaries.

 

like bad83 said, the carb is backwards. the primaries feed the center housing and secondaries to the front and rear. then swap ur float bowls so ur fuel feed will still be on the firewall side. and the throttle cable pulls from the bottom of the carb linkage.

 

Ok, i spun the carb around and i got the same results, wont idle under 2000 rpm.

 

also a friend suggested using a open spacer plate between the manifold and carb to pull more air through the primary ports, he said this might fix my problem with under 2000 rpm no fuel gets delivered through the carb. He said the more ait that gets pulled through might help but might mess with my transition between primary and secondary ports.