I was having a bit sluggish off idle performance from my Holley 850 carburetor so I decided to try switching to a Demon annular booster carb. I called a local speed shop and asked them if they carried BG Demons. The salesman told me that they stopped selling them since he burned his car down and had 7 of them returned from leaking problems. Discouraged, I called Summit, who also said that they were getting too many complaints about them and then decided to stop selling Demon carbs. I called Jegs, who was selling them. They said that BG carbs had some issues with metal shavings in the early years of production that caused leaking problems. However, the tech person told me that those problems are not common anymore. I called BG Demon carbs and you can predict what they told me. I really wanted to have a carb with annular boosters for better response. My Holley does not run cleanly until I get it up to 2000 rpms. Below that it seems sluggish and hesitant. I bought a Mighty Demon 850 with annular boosters, put it on the car and primed it by removing the coil to distributor wire. HOLY POSEIDON ADVENTURE!! Yup, it was a gasoline tsunami!! What a pile of rubbish! Gasoline was pouring out of it from every crack!! I really wanted it to work out but there is one thing more important than how my car runs and that is that I don't burn it to the ground.

 

My Race Demon works fine right out of the box, do you have the correct bowl fittings for the Demon they are different than the Holley. I suggest that you put the Holley back on and find out why you are getting off idlle stumble or hesitation first, it is not likely annular boosters is going to solve that kind of problem

 

The Holley has been running like that ever since I had it. I have changed everything in the motor since; heads, cam, intake manifold, etc. The only thing that I held over was the Holley 850 (burp, burp) which is nothing more than a gas dumping pig, to be blunt. It is not because of the open plenum intake because it did the same thing before I modified the engine and had a dual plane intake. The only thing that I can say good about the Holley is that it did not leak. It was always too rich and there was always hesitation until the engine hit about 2k rpms.

 

One more good thing you forgot about the Holley, If you ever park in a hill the make excellent wheel chocks!

 

What's your engine?

 

454, 11:1, solid roller cam, AFR aluminum heads. To answer the other member, I bought the adapter and dual feed for the Demon. That was not where it leaked. It poured gas out from just about everywhere else, especially from the diaphragm in the back. I called Jegs and asked them how they would feel about sending me a check for 60k to replace the vette that they nearly burned to the ground. I realize that they did not manufacture the carb but maybe they will take another look at what kind of rubbish BG Demon is putting on their shelves. Summit doesn't carry them anymore, my local speed shop said they refuse to sell them because they leak like a fishing net and I just bought one and it was laughable. Perhaps I should look into putting on a throttle body. It would be nice to have something that runs well yet does not spew gas like a well operating sprinkler system.

 

There is no reason the Holley shouldn't have worked properly, with a little help, naturally. Throwing parts at it -- in this case, very expensive carbs with annular boosters -- isn't the solution.

But I'm no expert. But perhaps if I say the magic word -- Lars -- a solution will be forthcoming! (Be patient. The great guru of all things carbureted doesn't show up every single day.)

 

Well, I am not an expert either. My brother is a mechanic though and he always told me that Holleys make power because they dump a lot of gas. He also told me that they are primitive junk because all they do is dump loads of gas, without any precision, whatsoever. That is exactly how mine felt. It never felt like it worked well so I was looking for alternatives. I didn't expect to take a gasoline shower, compliments of Barry Grant and his Demon Douser! The way I look at it; they don't seem to be very careful about their quality and now they have paid the price by the fact that I wrote this post. It does not help a business to have bad information floating around and apparently I am not the only one who took a Demon gas bath.

 

LOL, how true it is. With a lot of patience they can be made to work just fine.

First week I had mine it was flooding the car and dumping fuel by the buckets, when shut down it would drain fuel from the bowls into the motor..

I found some metal shavings stuck in the needle and seat, and the baseplate screw was tapped into the power valve area where it let fuel through.

The third carb I got from BG has worked great, but should it really take THREE!?

 

Yet you still paid big bucks for the carb. Will you return it? Will they accept the return? A few bad words won't discourage many, and yet your wallet is much more empty.

I hate to disagree with your brother, but the Holley could have been properly tuned from the get-go to work just fine. There are some very fine carb tuners on the forum, Lars among them. And if you are patient they will help you figure out your specific problem.

 

The carb is brand new, so of course they will take it back. I am not about to spend $500 on a gas sprinkler! They are going to pick it up on Monday via Fed Ex. Maybe Lars will jump in if he sees this post and help give some advice. I would still rather have a carb with annular boosters and was never happy with the Holley.

 

when i got my speed demon the float bowls were loose, and the secondary linkage was binding so bad, they wouldnt open. ive never been able to get the idle eaze to work and the carb is just one problem after another

 

Wow, I've never heard anything bad about Demon before. I was planning on ordering one this winter.

Is this a problem that can develop overtime or will it happen immediately if it's going to happen?

 

So Holley's are no good and neither are Demon's what are you going to put on ?

 

Why these of course!!

 

I wouldn't recommend priming a Demon carb by the procedure you followed. I always fill the bowls on my demon by using a small funnel and pouring gas down the vent tubes. If the bowls are dry, a sudden rush of fuel in there can screw up your float and cause fuel to run up and out of the vent tubes. I would pay close attention to your float levels for awhile. Just my .02 ...

 

Good point. Not everyone can afford Lingenfelter FI.

 

Motorhead, finally someone here sees the light, that's going to be so awesome, 4 double downdrafts..are you going for IDAs or IDFs??? (the base is different)

 

A Q-Jet.

Hello?

 

Holley's need to be fine tuned...

You can try a Edelbrock carb., they are good too...