demon issues/quick fuel question

[gmjj13]

well it seems as though my demon needs to be sent back to be repaired. apparently there's something wrong with the metering block. the secondaries just dump fuel into the engine without the engine even runnning. my engine builder took the carb apart and found a few small shavings, nothing major, cleaned everything put it back together with new gaskets and the same thing. checked the fuel pressure to make sure it wasn't too high, it was at 7.5, we lowered it to 6. adjusted the float level all the way down, and the secondaries are still dumping fuel. this sucks. i was told to ditch the demon and go with a holley or quick fuel carb. we ended up ordering a quick fuel 750. just wondering how many other people have had problems with demon carbs, and if anyone was running a quick fuel carb and how they like it. thanks...

[Shaker455]

Jeff,
I wrote a bit on the Performance Years forum:

http://forums.performanceyears.com/forums/showthread.php?t=482459&highlight=demons+demise

Jeff

[gmjj13]

couldn't seem to find it. can you post a link to the post? thanks...

what do you think about quickfuel carbs?

[CRead01]

I have had 3 demon carbs and have been happy with all of them. I have heard of a few people not being happy with them but most of the people I have heard of not being happy with them put too big of a carb on. a couple of the people though have talked about shavings in them.

even though I have been happy with mine I would be a little reluctant to buy another one just because of a couple problems I have seen with other people and heard online.

[yellow heap]

I Had a few probs with my Demon when I first got it-Shavings+ two undrilled idle holes-after I fixed that It works great.
I got my demon About 6 years ago.

[fastback]

My Demon was so bad that when it finally left me stranded at an Ocean City MD Cruise Weekend, 200 miles from home, I ripped it off, threw it in the dumpster at our hotel and bought a Holley from one of the vendors at the show.

Same problem. The carb just dumped fuel, unregulated.

[gmjj13]

wow. glad to hear that i'm not alone on having issues with demon. as far as the carb being to big, i would think that a 850 mighty demon would be just about right for my 496 BBC. i'm sure once i get it back from BG, it should be good to go. then i can atleast try to sell it for what i have in the quickfuel. as far as that goes, i got it put on last night, started right up and idled. just had to adjust the floats and idle circuit. i was amazed at how much just changing a carb could do. it sucks that demon has such a bad rep, just wish i would have known more about it before i bought my carb. oh well, lesson learned...

[kmcanally]

Usually dumping fuel is a blown power valve...I had a Demon and replaced it with a Quick Fuel...no problems.

[class67]

Oh man, you guys are scaring me...lol

I've had my 750 speed demon for three years with no problems at all....hopefully reading this thread will not jinx it.

[BRUNO.L]

My demon sucks, at first I thought it was the altitude in CO. but after putting on a couple different Hollies and even an edlebrock i realize its my speed demon. i cant seem to get my idle to stay low enough. My engine is contantly running past 1100 RPM, if i do get it to idle any lower it cuts off when i put it in gear.

[gmjj13]

well, got my demon back from BG. ended up being cleaning debris stuck in a vent tube that was causing the carb to dump fuel, according to their tech guy. BG checked it out, fixed it, and sent it back. i guess the only good thing about it all is that it only cost me shipping to them to get it fixed. had i not had so many problems with the demon carb, and had to send it back, i may have been able to bring my car to RTTH.:banghead:

[Shaker455]

Jeff,
If your up and running now call it a win!

[gmjj13]

yep, thats what i was thinkin...just want to let people know what they can expect from BG...thanks

[modularboy]

here my Demon experience

i expected a great carb,. got nothing but junk and a empty wallet , because it had to be shipped overseas, tax-duty and such, it costed me around 700 dollars for a Demon,

i had it for 130 miles on the car, i never could get it right, always running rich , and after 130 miles and using 17 gallons of fuel on a 90 mile roadtrip. i had another look at it,. with the engine running, fuel was running out between the baseplate/throttleshafts, so i took it off,

found shavings everywhere, holes in the metering plate drilled in various different angles where they should be the same and straight,different sizes holes for the booster venturi in the main body on the primary side, throttle shafts had so much play in them,

i still found 1 good use for it, and that was this

https://static1.pt-content.com/images/pt/2008/01/DSC01976-1.jpg

its a great ashtray..


and for BG's customer service??

heard nothing from them....:machine:

and now i have a QFT carb, that thing is so much better than the Demon, and its doing it while looking cool!

[CarPlayLB]

My first Demon carb (vacuum secondary) leaked fuel from underneath the rear float bowl due to a casting flaw in the un-used acc pump boss...sold it half price! Bought a 100 CFM smaller (the 625 vac sec) and it had the same secondary float bowl issues. Carry a flat screwdriver and a 5/8 wrench at all times! Seems the needle valve would stick open randomly and just dump fuel. Thank God for a strong MSD ignition. It is not the power valve as it is located in the front metering block.
I finally wound up fixing my Demon carb by switching to the one that says Holley on the ends! The car runs better and works perfect! I have the polished 670 Avenger vac sec carb...best way to fix a Demon!

[Shaker455]

I updated the link I posted eariler in this thread.

http://forums.performanceyears.com/forums/showthread.php?t=482459&highlight=demons+demise