Oversized carb, or badly tuned holley?
#1
I bought this 85 GS yesterday for a GREAT deal. I was told the only thing wrong was a snapped throttle cable. Check it out, and when I get there, I noticed it already had a holley carb, RB manifold, and full true dual RB exhaust. SWEET... And some other choice upgrades I keep finding...The guy didn't have a battery so i never even tried to start it. I figure, at this price, I'm taking it no matter what...
So today I fix the throttle cable and change the plugs, then do a few other precautionary things to make sure I don't ruin it on the first start up. Including spraying a bit of carb cleaner into the carb before start up. I have no idea how long it's been since it's been cranked over... Turn the key, it starts right up runs for a few seconds then dies. Try to restart, no go. Spray some more carb cleaner, boom... cranks up just fine. I continue to spray a bit of carb cleaner before each time I start it or it will not start up. So I turn the idle screw so the carb is a bit more open for start up, it cranks up and holds idle clean at 2500 for a little while then starts to die out as I am turning the idle screw down. I do this a few times and every now and again, I try to throttle it (all of this done standing over the engine, not with the gas pedal) it I throttle it really soft, it will rev up smoothly. But i have to do it very slow. if I just try and throttle it, it just bogs and wants to die.
It never stayed running on it's on more than one minute. And it will only start if I spray some carb clean before hand.
I do not know if it's a 600cfm or another size, The guy didn't even know what the racing beat manifold was called... So any guesses, to large of a carb, or badly tuned and need to be rebuilt? (by rebuilt, i mean the carb, not the motor)
So today I fix the throttle cable and change the plugs, then do a few other precautionary things to make sure I don't ruin it on the first start up. Including spraying a bit of carb cleaner into the carb before start up. I have no idea how long it's been since it's been cranked over... Turn the key, it starts right up runs for a few seconds then dies. Try to restart, no go. Spray some more carb cleaner, boom... cranks up just fine. I continue to spray a bit of carb cleaner before each time I start it or it will not start up. So I turn the idle screw so the carb is a bit more open for start up, it cranks up and holds idle clean at 2500 for a little while then starts to die out as I am turning the idle screw down. I do this a few times and every now and again, I try to throttle it (all of this done standing over the engine, not with the gas pedal) it I throttle it really soft, it will rev up smoothly. But i have to do it very slow. if I just try and throttle it, it just bogs and wants to die.
It never stayed running on it's on more than one minute. And it will only start if I spray some carb clean before hand.
I do not know if it's a 600cfm or another size, The guy didn't even know what the racing beat manifold was called... So any guesses, to large of a carb, or badly tuned and need to be rebuilt? (by rebuilt, i mean the carb, not the motor)
#3
It has a holley fuel pump and regulator also. I think it is flooding it badly...
The fuel pressure was close 7 psi. And I'm pretty sure a stock or street ported 12a with a holley will only need about 3.4 psi.
From what I have seen, a holley 465cfm carb is the best choice for a stock or street ported 12a.I'll see if i can trade this 600 for a 465 locally...
The fuel pressure was close 7 psi. And I'm pretty sure a stock or street ported 12a with a holley will only need about 3.4 psi.
From what I have seen, a holley 465cfm carb is the best choice for a stock or street ported 12a.I'll see if i can trade this 600 for a 465 locally...
#5
600 on a stock port is over kill. Ive seen people drill the high speed air bleeds and idel air bleeds. Their right next to the venturies,,, i think thats what thoes things are called their pressed in. Probably just on the primary side I dont know what size their supposed to be but im sure u can tell if they have been fucked with u need. a small holley 450-5 something.
Unrelated, topic Yo man r u a part of the central florida rotary club thing? Ive heard rummors about them doing a swapp meet and or car show?????? just wondering if u had some more info since they meet out your way
Unrelated, topic Yo man r u a part of the central florida rotary club thing? Ive heard rummors about them doing a swapp meet and or car show?????? just wondering if u had some more info since they meet out your way
#7
I have ran a 600 Holley on a stockport that ran perfectly and got 22.5 mpg. It's all in the tuning. The Holley has to run at 6-8 psi fuel pressure. If you look on the front of the airhorn on the carb, you will find a set of numbers. These will tell you what model the carb is. If the numbers are 1850-***, this would indicate a 600 cfm Holley.
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