Carb Fuel Leak

[FJ12IRL]

Hi All,

I've had a fuel leak from my carb from day 1 on my '91 fuel pump 3XW, so I decided to buy a rebuild kit and clean them.

And as I had the time, I did the job today..

I should mention that I am no stranger to Mikuni CV carbs and have done many in my time but this leak from the choke breather pipe is still there.
Even after a full overhaul and 1mm holes drilled in the body to avoid siphoning, it's still leaking.

Are there any other things I'm missing?
Would a fuel cutoff solenoid help?

Any help /advice appreciated

[Pat Conlon]

Tell us more....Start with the fuel pump. Does it dribble gas when the pump is off?
Do the carbs leak when the engine is turned off, or just when the engine is running?

Which carb is leaking? More than 1?

When you say you "rebuilt" them, does that mean you installed new float needles and needle seats and seat O rings?

[FJ12IRL]

Tell us more....Start with the fuel pump. Does it dribble gas when the pump is off?
Do the carbs leak when the engine is turned off, or just when the engine is running?

I've only noticed them leaking after running the engine..

I've only leaks from the choke vent tubes too.

[Pat Conlon]

Sorry, I was editing while you posted...

New float needles, seats and O rings?

[FJ_Hooligan]

Where do you have the float bowl vent and choke intake hoses routed?

Around the heat shield on the right side and into the wire loop behind the case?

[FJ12IRL]

Sorry, I was editing while you posted...

New float needles, seats and O rings?

Yes, all new o rings, needles, jets, air screws and gaskets.
Float heights checked also.

[FJ12IRL]

Where do you have the float bowl vent and choke intake hoses routed?

Around the heat shield on the right side and into the wire loop behind the case?

Yes, routed correctly.

[Pat Conlon]

Sorry, I was editing while you posted...

New float needles, seats and O rings?

Yes, all new o rings, needles, jets, air screws and gaskets.
Float heights checked also.

Fuel levels ok?  Is it coming from 1 carb or many?  ( I number my choke vent hoses)

[FJ12IRL]

Sorry, I was editing while you posted...

New float needles, seats and O rings?

Yes, all new o rings, needles, jets, air screws and gaskets.
Float heights checked also.

I think its coming from 1 and 4


Fuel levels ok?  Is it coming from 1 carb or many?  ( I number my choke vent hoses)

[FJ12IRL]

So..
I charged up the battery and tried to work out why my carbs are leaking and..
It didn't leak at first, even after a while running. Though I did notice when I blipped the throttle, she took a little while to return to idle.
Then when I stopped the engine, she dumps a load of fuel out of #1 and #4 choke vent tubes..
and now, when I run the pump, it's a gusher..
I'm thinking now that my fuel pump is faulty or maybe I've set my floats too high..
Anyone have any thoughts how I can fix this?

[Pat Conlon]

1) Set your floats at 24.5mm (measure from the top of the curved portion of the float)
2) Check your fuel levels

Is it possible you installed the larger float needle seats used for the gravity flow carbs?
http://www.fjowners.com/index.php?topic=9836.0

[FJ12IRL]

Well, today I removed the carbs again and set the heights to 24mm (they were at 22.5) and checked that I had the right jets for my fuel pump setup.
I also checked my pump for faults and it seems to work fine.
Checked the routing for the overflow and choke vent pipes and made sure they had no kinks in them.
Put the tank back on, turned the fuel tap on, ignition on let the pump run then stop as it hit the float needles and waited for the gusher..
No leaks..
So then I pullled the choke out fully and hit the starter, she lit up straight away and ran smooth, again, no leaks..
after running her for a while, I took her off choke and blipped the throttle a few times she took a little long to return to idle but I'm putting that down to not having balanced the carbs or set the idle mixture screws yet.
But still no leaks!!
It appears I've fixed the leaks for now, fingers crossed..
Thanks to all for your help

[Pat Conlon]

 

[fj1289]

Awesome!  Thanks for posting the solution/follow up.   Always good to know how things turned out!