New carb base leaking, fix or..?

[Jonas Nordstrom]

Happy having my custom Carb finished I did some quick start test with the engine to set float levels etc and check for leaks.

.....and my new quick fuel base just pours fuel from the secondary shaft, both sides.

Can this be fixed with those shaft nylon bushings?
Or should I get a brass bushing kit? (Lots of work on a brand new base..)
Or just find another base?

Also, i can wiggle the secondary shaft up and down.
(I have contacted the seller though but I bought this before christmas and finished up the carb now.)

Thanks

 

[493 Mike]

Sounds like the rear float is not sealing. I would pull the rear bowl and inspect the needle and seat and blow it out thoroughly. Recheck the float levels.
Mike

 

[jt4406]

There is no fuel standing around the throttle shafts, do you have a good inline filter, or the brass filters in the bowls? If it is leaking, it's because the rear bowl is overflowing, float level too high, or most likely, something caught between the needle and seat. Shut the engine off, remove one lower rear bowl screw to drain bowl (catch fuel in suitable container) restart, and watch rear venturi clusters for either to start dripping, if they do, shut it off and try again. Do this a couple times. If something is caught between the needle and seat, this will, (sometimes) flush it out. If this doesn't work, remove the rear bowl, turn it upside down and make sure the initial bowl setting is correct. My .02 jess

Mike beat me to it!!

 

[Jonas Nordstrom]

There is no fuel standing around the throttle shafts, do you have a good inline filter, or the brass filters in the bowls? If it is leaking, it's because the rear bowl is overflowing, float level too high, or most likely, something caught between the needle and seat. Shut the engine off, remove one lower rear bowl screw to drain bowl (catch fuel in suitable container) restart, and watch rear venturi clusters for either to start dripping, if they do, shut it off and try again. Do this a couple times. If something is caught between the needle and seat, this will, (sometimes) flush it out. If this doesn't work, remove the rear bowl, turn it upside down and make sure the initial bowl setting is correct. My .02 jess

The fuel is the float level that was way to high as I hadn't set it yet.

Though if fuel comes through, wont that be a major vacuum leak later on when driving?

 

[jt4406]

Not if the throttle shaft/hole isn't worn out (unlikely on a newer carb, especially on secondary). Some clearance is necessary to prevent the throttle shaft sticking with normal thermal expansion.

 

[Jonas Nordstrom]

Not if the throttle shaft/hole isn't worn out (unlikely on a newer carb, especially on secondary). Some clearance is necessary to prevent the throttle shaft sticking with normal thermal expansion.

Thanks, maybe I am overthinking it.
Though I have 6 used Holleys in the garage and none of them has as much wiggle room as this new QFT base, so it feels a bit sketchy.

 

[jt4406]

custom Carb finished

You did mention this, which usually requires disassembly of carb. There are plastic bushings that fit around some throttle shafts that may have gotten misplaced or forgotten which may be causing the sloppiness you have. (just thinking out loud, no judgement intended).

 

[Jonas Nordstrom]

You did mention this, which usually requires disassembly of carb. There are plastic bushings that fit around some throttle shafts that may have gotten misplaced or forgotten which may be causing the sloppiness you have. (just thinking out loud, no judgement intended).

No problem.
Though this base was bought brand new and assembled. So right now I'm thinking about taking it apart to see if those plastic/nylon bushings are there.

 

[jt4406]

I would do the same, but be aware, the shaft screws are usually staked to prevent them from backing out and falling into the motor if they were to vibrate loose (and should be restaked upon reassembly). You may need to file the end of them to prevent them from breaking off in the shaft (major discombubalation!).

 

[Jonas Nordstrom]

Thanks.

Yes, will order some new shaft screws first.
I just removed the throttle plates from a Carter and a Quadrajet, so got some practice.

 

[1STMP]

An easy way to check for integrity of the
needles and seats: Remove the carb and drain
any fuel in the bowls. Attach a vacuum pump
and hose to the fuel inlet, invert the carb and
press the vacuum pumps' handle a couple
times to see if the vacuum holds. If no
vacuum there is definitely a problem. There's
some debris obstructing the seal or it could
be the float is stuck.