We have a 600 holley on a 312 and just can't get it to stop flooding out.We can get it running but have to hold it half throttle to keep it running.We have set the float levels,gas is below the sight plugs in both ends.New power valve and new acc.pump.Floats are not ruptured.New needle and seat(tried several)Fuel pump is stock manual with 4-6 lbs.Tried electric with anywheres from 3 to 10 lbs,no difference.Put on the other holley we had and ran fine.What are we missing?
4b316
Stuff
New pump spring and dia.Tried 2 of them to make sure.Adjustment is spot on.No leak in the bottom and no teflon tape.Float levels are fine,even a lttle low.Really got me stumped especially with the other one working fine.There was a little water in it when we took it apart,maybe split and froze something?
New pump spring and dia.Tried 2 of them to make sure.Adjustment is spot on.No leak in the bottom and no teflon tape.Float levels are fine,even a lttle low.Really got me stumped especially with the other one working fine.There was a little water in it when we took it apart,maybe split and froze something?
Make sure the check valve is in place under the accelerator pump squirter. If it's not there, fuel can siphon over into the primary side when the engine is running and flood it.
It is # 74 or 75 or 76 in the view HERE.
Also be sure washer #73 is there, its a rubber-coated thin aluminum piece. Only one, sometimes they will stick to the body and two will accidentally be installed.
It is # 74 or 75 or 76 in the view HERE.
Also be sure washer #73 is there, its a rubber-coated thin aluminum piece. Only one, sometimes they will stick to the body and two will accidentally be installed.
Holley issues
Oh come now fellas! Don't over think things! I have a Holly 600 Vac Secondary on a 307 Chevy in a 1968 Camaro, and it has done the very same thing. Is this carb a double pumper or a Vac secondary? Either way, I've had the same problem on both. Fuel flooding over the throttle plates from the idle-air bleeds, then kicking the idle up to 2500 or holding the pedal down just to keep it running? Don't over think things guys! The floats are stuck! A light or medium rap of a hammer (or rock, and trust me, I've done this.) on the top of the float adjuster should do the trick, if you are stuck far from home. Once you get home, check the float level. If it's too high, drop it down with your handy-dandy screwdriver. If it still hangs up, crack the float bowls off and clean the needle, seat, float pivot, and so on. Violla! A hitch-free Holly 600. Sorry if I sound so abrupt, but guys, this is a Holly, a pain in the *** to tune sometimes, but the most adjustable carb on the market! Think simple first, the smallest and most insignificant of things can throw the whole smash off kilter.
Oh come now fellas! Don't over think things! I have a Holly 600 Vac Secondary on a 307 Chevy in a 1968 Camaro, and it has done the very same thing. Is this carb a double pumper or a Vac secondary? Either way, I've had the same problem on both. Fuel flooding over the throttle plates from the idle-air bleeds, then kicking the idle up to 2500 or holding the pedal down just to keep it running? Don't over think things guys! The floats are stuck! A light or medium rap of a hammer (or rock, and trust me, I've done this.) on the top of the float adjuster should do the trick, if you are stuck far from home. Once you get home, check the float level. If it's too high, drop it down with your handy-dandy screwdriver. If it still hangs up, crack the float bowls off and clean the needle, seat, float pivot, and so on. Violla! A hitch-free Holly 600. Sorry if I sound so abrupt, but guys, this is a Holly, a pain in the *** to tune sometimes, but the most adjustable carb on the market! Think simple first, the smallest and most insignificant of things can throw the whole smash off kilter.
Maybe you missed:Speedshift_Sam said:
If the float(s) were stuck open, the fuel level would continue to rise.
If they were stuck shut, there would be no fuel.
If you have phenolic floats they absorb fuel, toss em for the older style brass or the new hollow white plastic ones.
Been down that road before with the phenolic floats, they seem fine and when you check the fuel level it seems to be OK but the floats are heavy with fuel and they won't push hard enough against the seat to shut the fuel off once the rpm comes up.
If thats not it, I would check the accelerator pump check valve or rubber umbrella to make sure it is working and functional.
Been down that road before with the phenolic floats, they seem fine and when you check the fuel level it seems to be OK but the floats are heavy with fuel and they won't push hard enough against the seat to shut the fuel off once the rpm comes up.
If thats not it, I would check the accelerator pump check valve or rubber umbrella to make sure it is working and functional.
The float issue
I'd hate to sound as if I am contradicting any of you, however I have had the very same things happen on the '68 camaro carb, an older style brass float, center hung carb. Don't ask me why, but they do hang up once and a while, especially on unleaded fuel. I had to bang on the float bowls for a few minutes with a ball-peen hammer to even make it back up the south St. Vrain Canyon to our shop to even begin to diagnose the problem. (Which was exactly that, the floats had stuck.) Start with the floats, eliminate the simple first before diving into the inner workings of the dumb thing.
If anyone has issues with this, feel free to PM me you guys, I've spend the better half of my life tuning carbs and building engines for street and endurance racing. Feel free to rake me over the coals.
I'd hate to sound as if I am contradicting any of you, however I have had the very same things happen on the '68 camaro carb, an older style brass float, center hung carb. Don't ask me why, but they do hang up once and a while, especially on unleaded fuel. I had to bang on the float bowls for a few minutes with a ball-peen hammer to even make it back up the south St. Vrain Canyon to our shop to even begin to diagnose the problem. (Which was exactly that, the floats had stuck.) Start with the floats, eliminate the simple first before diving into the inner workings of the dumb thing.
If anyone has issues with this, feel free to PM me you guys, I've spend the better half of my life tuning carbs and building engines for street and endurance racing. Feel free to rake me over the coals.
ok ive been trouble shooting the same type problem a on a dual quad (holley) on a blower motor,,after almost hydraulicing the motor,,i went thru the carbs every thing inside was fine but replaced every thing any way due to it had been 3 years since and with todays gas they recomend doing it every year,,no need for that in my eyes unless you have hardening of the rubber parts,which i did not,,,which the carb refresh didnt not help at all,,still flooding the motor
i finally drained the fuel cell, flushed the system, added new gas,,i made a funnel with cheese cloth as a filtering device and it runs great now,, i did try to filter the old gas several times but it kept turning the cheese cloth black.. so it appears that i had a bad batch of gas lots of junk in the fuel cell and some thing black in the gas,,,now where to dump about 7 gallons of dirty gas,,
i do think i remember the last gas station i used just before the trouble,,on my way back from wheels of time event at macungie PA i filled up at turkey hill,i have filled up there every year going to this event,,on the way home the car started running like crap,,,,it may have been the bottom of there tanks i dont know for sure
the main thing is i caught the problem trying to start the car one day, i could hear the motor turning over gettign slower and starting to hydrulic,,,wheew,, seems to be fine now,,,
i finally drained the fuel cell, flushed the system, added new gas,,i made a funnel with cheese cloth as a filtering device and it runs great now,, i did try to filter the old gas several times but it kept turning the cheese cloth black.. so it appears that i had a bad batch of gas lots of junk in the fuel cell and some thing black in the gas,,,now where to dump about 7 gallons of dirty gas,,
i do think i remember the last gas station i used just before the trouble,,on my way back from wheels of time event at macungie PA i filled up at turkey hill,i have filled up there every year going to this event,,on the way home the car started running like crap,,,,it may have been the bottom of there tanks i dont know for sure
the main thing is i caught the problem trying to start the car one day, i could hear the motor turning over gettign slower and starting to hydrulic,,,wheew,, seems to be fine now,,,
holly 650 flooding on a 289
hi guys...been reading about the flooding business...after much thought...whats your input on the throttle rod( yknow the rod that operates the butterflies)...how much play will it tolerate before flooding the engine???....another thing is...If the base plate is allowing air leakage...what can I do to seal it up???...hope someone knows cuz I rebuilt the carb and the car has sat without running at all for three years( no fuel in it at all)....also...is it possible to have installed the wrong kit????..ok ok...too many questions, but thanks if you have some suggestions...ole Rich
hi guys...been reading about the flooding business...after much thought...whats your input on the throttle rod( yknow the rod that operates the butterflies)...how much play will it tolerate before flooding the engine???....another thing is...If the base plate is allowing air leakage...what can I do to seal it up???...hope someone knows cuz I rebuilt the carb and the car has sat without running at all for three years( no fuel in it at all)....also...is it possible to have installed the wrong kit????..ok ok...too many questions, but thanks if you have some suggestions...ole Rich
Why does everyone hate Holleys?
Boy, sometimes help isn't very helpful. Let's see if the Holley Gods can help you.
If your leaking air at the throttle shaft, your seals are shot and causing a lean condition, not flooding. If air is leaking at the baseplate, more than likely it is a failed or improper base gasket. (I also suggest checking for open vacuum nipples, or leaking nipple caps.) And yes, it is very possible to put the parts for one holley into a different one. Some parts do interchange, while others are very specific. You can nearly overhaul a vacuum secondary holley with a rebuild kit for a double-pumper, but that leaves you high and dry for the diaphragm and spring, which most often fail.
Holleys are finicky, there is no denying that. Edelbrocks work just fine out of the box, no denying that either. But therin lies the problem. Holleys are, for lack of a better term, street-fitted racing carburetors, and they act like it. All it takes is a little patience and logic, and you'll have something that you'll never have to fiddle with again. Edelbrocks take a heck of a lot of fiddling if you want to make them do something better or more specific. So, what's the beef? It took us a full season of swapping jets, power valves, squirters, pump cams, and even metering blocks before we had it just right. It has been ten seasons since then, and our roadrace '67 camaro has had nery a hiccup with a Holley. It's blown up a few times, but never at the fault of the carb. (Usually the driver's leadfoot and over-revving on the downshift.) As for the mileage question, If Holley's are so terrible, why is it I'm getting 17mpg out of one on my hot 327 in a '68 Camaro? Or how about the 21mpg we get out of a Holley equipped 350 in a '74 'Vette? The point is, if you have a little patience, and a want to make it right and not settle for the easy fix, then fiddle with your Holley. Get it right and it will be right, no worries. I hope I have been of some help, and if anyone got their feathers ruffled, well, I guess I'm too dogged and determined to settle for something out-of-the-box.
All hail the Godess of Carburetion.
Boy, sometimes help isn't very helpful. Let's see if the Holley Gods can help you.
If your leaking air at the throttle shaft, your seals are shot and causing a lean condition, not flooding. If air is leaking at the baseplate, more than likely it is a failed or improper base gasket. (I also suggest checking for open vacuum nipples, or leaking nipple caps.) And yes, it is very possible to put the parts for one holley into a different one. Some parts do interchange, while others are very specific. You can nearly overhaul a vacuum secondary holley with a rebuild kit for a double-pumper, but that leaves you high and dry for the diaphragm and spring, which most often fail.
Holleys are finicky, there is no denying that. Edelbrocks work just fine out of the box, no denying that either. But therin lies the problem. Holleys are, for lack of a better term, street-fitted racing carburetors, and they act like it. All it takes is a little patience and logic, and you'll have something that you'll never have to fiddle with again. Edelbrocks take a heck of a lot of fiddling if you want to make them do something better or more specific. So, what's the beef? It took us a full season of swapping jets, power valves, squirters, pump cams, and even metering blocks before we had it just right. It has been ten seasons since then, and our roadrace '67 camaro has had nery a hiccup with a Holley. It's blown up a few times, but never at the fault of the carb. (Usually the driver's leadfoot and over-revving on the downshift.) As for the mileage question, If Holley's are so terrible, why is it I'm getting 17mpg out of one on my hot 327 in a '68 Camaro? Or how about the 21mpg we get out of a Holley equipped 350 in a '74 'Vette? The point is, if you have a little patience, and a want to make it right and not settle for the easy fix, then fiddle with your Holley. Get it right and it will be right, no worries. I hope I have been of some help, and if anyone got their feathers ruffled, well, I guess I'm too dogged and determined to settle for something out-of-the-box.
All hail the Godess of Carburetion.
Had a similar issue recently. I changed the needle and seat, tested the power valve and still had the issue. Fuel was pouring out of the boosters. Finally I took the metering block off and blew compress air through the passages. A chunk of crap came out of one of them and it has been fine since. I think something was plugged in the idle circuit somewhere and it was back feeding to the boosters.
Interesting.. I had a holley 600 I picked up used.. NOTHING I did to that POS would make it work right.. then I finally figured out that the single-feed transfer tube was causing problems with not getting enough fuel into the secondary bowl...
I replaced it with a brand new Holley 650 vac secondary, with dual feed (which also meant I got real jets in the back as well as the front, no more stupid 'plates') car runs AWESOME since.. those single feed carbs are ok for grannies 283 that may hardly ever see the secondaries open.. wouldn't waste my time on them for anything else.
I replaced it with a brand new Holley 650 vac secondary, with dual feed (which also meant I got real jets in the back as well as the front, no more stupid 'plates') car runs AWESOME since.. those single feed carbs are ok for grannies 283 that may hardly ever see the secondaries open.. wouldn't waste my time on them for anything else.
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