6 pack fuel problems

[al383]

I have a 1969 superbee , With a stroke 440 When I leave the car sit for A few hours all the fuel from the carbs leak into the engine I took the carbs apart check the floats to see if the tab was bent . Needle seats were good no dirt Put it all back together check the level in the fuel bowls , everything is good. Any help to solve this would be greatly appreciated . Thank you

 

[pnora]

External leaks are most likely bowl caskets,bowl screw gaskets, metering plate gaskets or accelerator pumps. If its that bad you should be able to watch it leak and pinpoint the spot.

 

[RJRENTON]

I have a 1969 superbee , With a stroke 440 When I leave the car sit for A few hours all the fuel from the carbs leak into the engine I took the carbs apart check the floats to see if the tab was bent . Needle seats were good no dirt Put it all back together check the level in the fuel bowls , everything is good. Any help to solve this would be greatly appreciated . Thank you

Curiosity question.....is just one (center carb) or are the end carbs as well leaking? Is it a visable external leak or perhaps the center carb is leaking internally thru the power valve's gasket seat. The center csrb's accelerator pump well and diaphragm are also a potential leak point......just thinking out loud....
BOB RENTON

 

[al383]

Curiosity question.....is just one (center carb) or are the end carbs as well leaking? Is it a visable external leak or perhaps the center carb is leaking internally thru the power valve's gasket seat. The center csrb's accelerator pump well and diaphragm are also a potential leak point......just thinking out loud....
BOB RENTON

The center carb and the back carb are the ones that leak down , When my friend and I took the carbs apart we couldn't find any place where we thought it was leaking down few fuel pressure I put as low as 3 pounds came back a few hours later and still leaked down

 

[al383]

External leaks are most likely bowl caskets,bowl screw gaskets, metering plate gaskets or accelerator pumps. If its that bad you should be able to watch it leak and pinpoint the spot.

Nothing visible leaking on the outside

 

[Daves69]

Trouble shooting persistent leaking carbs on the engine can get to be expensive in oil changes. Were these recently rebuilt?

 

[1968rt]

Where did you buy the needle and seats? I bought a bunch off of ebay and they all leaked. you need quality seats.

 

[GrabberOrange69]

Is the float compromised? Just spit balling.

 

[al383]

Where did you buy the needle and seats? I bought a bunch off of ebay and they all leaked. you need quality seats.

They came with the carburetors set up that I bought from 6 pack performance out of Arizona

 

[al383]

Is the float compromised? Just spit balling.

No took the bowls off check the floats none of them were heavy . Check the tabs on them they weren't Bent

 

[al383]

Trouble shooting persistent leaking carbs on the engine can get to be expensive in oil changes. Were these recently rebuilt?

Throwing a year old the whole setup was brand new . I've had some issues with them ever since I bought them

 

[al383]

Trouble shooting persistent leaking carbs on the engine can get to be expensive in oil changes. Were these recently rebuilt?

You're right with the expensive oil changes

 

[Daves69]

You're right with the expensive oil changes

You might try something like this with mineral spirits........
https://www.forebodiesonly.com/foru...pack-carbs-now-it-wont-idle.23952/post-142177

 

[al383]

squirter on ctr. carb. leaking, how can i fix it.

 

[Daves69]

Hmmm, valve hanging up or missing? Seat fouled? Wrong or compromised gasket not sealing the pump circuit?

 

[lewtot184]

how does the engine start-up after the "leak down"? a leak down of that magnitude would be a difficult engine start-up.

 

[RJRENTON]

Hmmm, valve hanging up or missing? Seat fouled? Wrong or compromised gasket not sealing the pump circuit?

View attachment 1157637

USUALLY, a new check valve weight (# B-3318) is included in the rebuild kit, with nstructions saying: "using a small diameter drift pin, lightly tap the old weight with the drift pin a light hammer blow, forming a new seat, invert the body, allowing the old weight to fall out, then install the new weight, along with the proper gaskets, nozzle and discharge screw". This procedure fixes any pullover fuel delivery issues caused by a leaking check valve issue.
Another potential problem area is the use of NON HOLLEY inlet needle and seat arrangements. Some non Holley parts use a backward arrangement from the Holley design .... using the external slotted screw to adjust the float level, rather than the hex nut. Leaks can develop both internal and external to the float valve assembly. .....another point to consider...
Just my opinion of course.
BOB RENTON

 

[al383]

how does the engine start-up after the "leak down"? a leak down of that magnitude would be a difficult engine start-up.

Difficult engine start up is correct

 

[al383]

Hmmm, valve hanging up or missing? Seat fouled? Wrong or compromised gasket not sealing the pump circuit?

View attachment 1157637

 

[al383]

Hmmm, valve hanging up or missing? Seat fouled? Wrong or compromised gasket not sealing the pump circuit?

View attachment 1157637

Thank you I'll check that out