OP
@stollerscoot avatar
UTC

Hooked
1964 VBB
Joined: UTC
Posts: 139
Location: South Orange, NJ
 
Hooked
@stollerscoot avatar
1964 VBB
Joined: UTC
Posts: 139
Location: South Orange, NJ
UTC quote
Hey all,
My VBB has been leaking fuel down the rear of the engine and I can't figure it out.
I've removed the carb
I've used pipe cleaners to clear blockage
I've replaced all gaskets
I've replaced float needle
I've removed and reset float to ensure movement.
Fuel line and banjo are in tact.

I can't figure it out. Seems the overflow is the issue, but don't know what's wrong.
@mjrally avatar
UTC

Veni, Vidi, Posti
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
Joined: UTC
Posts: 5111
Location: Oceanside, CA
 
Veni, Vidi, Posti
@mjrally avatar
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
Joined: UTC
Posts: 5111
Location: Oceanside, CA
UTC quote
Have you pin pointed where gas is coming from? Dry it off real good, turn the fuel on and look with a flashlight where the carb shows liquid. Or dry it, use a paper towel to dab certain areas with the fuel turned on. It'll absorb fuel escaping helping you narrow the leak down.

9/10. I've seen it at the fuel banjo bolt or at the Chinamans hat. 1. Are both fiber O washers on either side of the banjo?

2. Is the rubber O ring on the inside lip of the Chinamans hat?

3. Is there a fiber washer underneath the head of the flat bladed screw that holds the chinamans hat on?

4. Is everything on and secure?
OP
@stollerscoot avatar
UTC

Hooked
1964 VBB
Joined: UTC
Posts: 139
Location: South Orange, NJ
 
Hooked
@stollerscoot avatar
1964 VBB
Joined: UTC
Posts: 139
Location: South Orange, NJ
UTC quote
Everything is on, secure and solid. My friend at ScooterMercato thinks it might be the needle not seating properly in the overflow. I'm going to replace the float assembly to make sure those components are all new
@mjrally avatar
UTC

Veni, Vidi, Posti
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
Joined: UTC
Posts: 5111
Location: Oceanside, CA
 
Veni, Vidi, Posti
@mjrally avatar
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
Joined: UTC
Posts: 5111
Location: Oceanside, CA
UTC quote
Stollerscoot wrote:
Everything is on, secure and solid. My friend at ScooterMercato thinks it might be the needle not seating properly in the overflow. I'm going to replace the float assembly to make sure those components are all new
Here's a test. Unscrew the two screws that hold the float assembly to the carb. Hold the float assembly in the air so you can see the float. Turn the gas on. Manually lift the float up and see if all gas stops flowing. Then let it drop. Repeat.

Thatll tell you if its shutting off like it should.
@hibbert avatar
UTC

Molto Verboso
Vespa
Joined: UTC
Posts: 1714
Location: California
 
Molto Verboso
@hibbert avatar
Vespa
Joined: UTC
Posts: 1714
Location: California
UTC quote
Not sure this is an issue on 20's but on the SPACO 24 the casting at the float cover thread can be too tall preventing a good seal on the cap. Check and file if necessary. If the cap looks wet could be.
OP
@stollerscoot avatar
UTC

Hooked
1964 VBB
Joined: UTC
Posts: 139
Location: South Orange, NJ
 
Hooked
@stollerscoot avatar
1964 VBB
Joined: UTC
Posts: 139
Location: South Orange, NJ
UTC quote
Thanks guys. The filter cap fits fine and there is no drippage from the top of the cap. As for the float, I'll reinstall a new one when it comes and see
OP
@stollerscoot avatar
UTC

Hooked
1964 VBB
Joined: UTC
Posts: 139
Location: South Orange, NJ
 
Hooked
@stollerscoot avatar
1964 VBB
Joined: UTC
Posts: 139
Location: South Orange, NJ
UTC quote
So, I received a new float and pin and after replacing mine, the leak seems to have been controlled.
My new issue, is that when I start the scooter, I rev the throttle, close the choke, the engine sputters and has no pickup (like it's not getting fuel).
I had cleaned the carb trying to solve the leak, but think I need to use pipe cleaners to make sure there is no blockage feeding fuel into the cylinder.
Anyone run into this?
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