or a 750-850 Demon
Holley help
Thread Starter
Instructor
Joined: Apr 2005
Posts: 104
Likes: 0
From: Salem Oregon
Holley help
OK, OK, I've got to get this off my chest. '69 coupe, was a 350/350, now is a 406. We've owned the car for many years. It's used as a daily driver in the summers and as a frustration release in the winters. We start it at least once a month to keep an eye on routine maintinance items. Car works well except for the carb. It's a holley 4779-6(0577) 750 double pumper, mech. seconds and four corner idle screws. This piece of crap runs like a rapped ape in a straight line, but stumbles in every corner. If you give it even the slightest amount of gas going around a corner, jerks hesitantly for a second. I've had two carb guys rebuild it, to no improvment. I'd like to scrap this junk, and get what? A 670 or a 770 Demon? Looking for opinions or owners that have cured this problem. Thanks
Instructor
Joined: Dec 2004
Posts: 124
Likes: 0
From: Gainesville GA
Originally Posted by Fstdraw
OK, OK, I've got to get this off my chest. '69 coupe, was a 350/350, now is a 406. I'd like to scrap this junk, and get what? A 670 or a 770 Demon? Looking for opinions or owners that have cured this problem. Thanks
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Thread Starter
Instructor
Joined: Apr 2005
Posts: 104
Likes: 0
From: Salem Oregon
Have not been able to make much differance one way or another. I spent $ 300.00 2 years ago for a total rebuild and ajustment(boy did I get screwed) and all it did was backfire on me with deceleration. Changing the float level does not make much diff. However, if the level is too high, it tends to bog down some. If I hammer the binders hard, the carb tends to kill the engine w/the rapid deceleration. Under full throttel, the car runs great, but you can only do that for so long. I saw on the internet a place that's a hour away that is good with these carbs, Savas Tuning Systems Inc., I just hate to flush more money down these old venturies. This carb has done this same crap for two different motors, two different ignition systems and two rebuilds. I once put this carb on my jet boat(454) and you could not have asked for a better performer. Who knows.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by GDaina
When the motor backfired, it blow the power valves...bet they don't hold vacuum
and if it's old, you may need throttleshaft bushings. You may have a warped baseplate or metering block. If Lars build Holleys too, I would send it to him. Else, send it back to Holley, they rebuild them economically and they do it right. They rebuilt the one on my boat and it made a world of difference.
Thread Starter
Instructor
Joined: Apr 2005
Posts: 104
Likes: 0
From: Salem Oregon
Backfire was through the exhaust. I understand that is a different set of problems from the carb., or could be. I don't think my problem has to do with the motor. I guess I could have an exhaust leek, but I hope not.
