From: nomorespameventhoughthejapanesespamgivesmeachuckle on
I just recently noticed a gas leak on my bike. I first noticed it
dripping from my left-most carb (#1). It was leaking from many
different locations that it should *not* be leaking through because of
gaskets (like the float bowl seam). It then started leaking from the
overflow on the crab.

Well, I took the gas tank off and found out that the petcock leaks. I
drained it and took apart the petcock and while everything *looked*
normal, I placed an order for a petcock rebuild kit (which will be here
on July 5th because of the holiday). Anyways, I played around with the
petcock last night by lightly pushing down on the diaphragm with a
flat-blade screwdriver. I reassembled the petcock and no leaks for
hours. I rode it around last night and parked it for the night. I
awoke in the morning to crab #1 flooded again. I unhooked the gas tank
lines and the petcock was leaking again.

Now my question:

Do I likely have a problem with just the petcock leaking or with a carb
too. I find it odd that only carb #1 leaks... but this may be due to
the fact that when I put the bike on the side stand that the lean
causes that carb to leak. By the way, I did rebuild carb #1 with a new
valve seat and valve needle after this happened the first time last
week because the needle was slightly worn; but this didn't seem to
help. Could I have a bad float in that carb? Thanks!

From: FB on

nomorespameventhoughthejapanesespamgivesmeachuckle wrote:
> It then started leaking from the
> overflow on the crab

It's not so bad when your crabs overflow. A little bit of mayonnaise
mixed with cooked shredded crab meat makes a nice sandwich.

Seriously, though, your float valve is either sticking or there is
trash on the float valve seat on that one carburetor. You might try
squirting some Berryman's B-12 down the fuel line to dissolve whatever
gum and varnish might be keepingthe float valve from sealing properly.

From: nomorespameventhoughthejapanesespamgivesmeachuckle on

FB wrote:
> nomorespameventhoughthejapanesespamgivesmeachuckle wrote:
> > It then started leaking from the
> > overflow on the crab
>
> It's not so bad when your crabs overflow. A little bit of mayonnaise
> mixed with cooked shredded crab meat makes a nice sandwich.
>
> Seriously, though, your float valve is either sticking or there is
> trash on the float valve seat on that one carburetor. You might try
> squirting some Berryman's B-12 down the fuel line to dissolve whatever
> gum and varnish might be keepingthe float valve from sealing properly.

But... I changed out the seat and the needle with known good ones out
of a rebuild kit and the problem still persists. Do you disagree that
there is definitely a problem with the petcock that it keeps leaking
-drip drip drip- when it's in the ON or RES position (it's vacuum
operated). I stored the tank for the entire winter with Stabil in it
and it never leaked once. I'm wondering if the petcock was the
original problem or if that became a problem because of another (i.e.
pressure built up and the gas had to go somewhere so it put a small
hole or tear in the diaphragm). I say this because I was watching the
problem persist as I was working on the bike and the leak started at
the carb and it wasn't until an hour later that a leak started to
develop from the petcock (not saying the petcock wasn't *leaking* then
it's just that the pressure built up so much that with the tank
attached gas was coming out of the seals and overflow screw on the
petcock.) Thanks!

=) Yeah spell check doesn't catch that but proofreading should... Guess
I should learn to proofread.

From: FB on

nomorespameventhoughthejapanesespamgivesmeachuckle wrote:

> But... I changed out the seat and the needle with known good ones out
> of a rebuild kit and the problem still persists. Do you disagree that
> there is definitely a problem with the petcock that it keeps leaking
> -drip drip drip- when it's in the ON or RES position (it's vacuum
> operated).

Yes, you might have a problem with the petcock diaphragm, the automatic
valve operated by the diaphragm, the spring that pushes the valve shut,
or you might have a bad grommet in the selector side of the petcock
which allows fuel to leak from the PRI side to the ON port.

The float in the left carb may be set too high, the needle valve could
be leaking, and there could be trash on the float valve seat that has
accumulated there since you installed the new seat.

> I'm wondering if the petcock was the
> original problem or if that became a problem because of another (i.e.
> pressure built up and the gas had to go somewhere so it put a small
> hole or tear in the diaphragm).

There just isn't that much fuel pressure in a gravity feed system where
the highest point in the gasoline level is maybe 12 inches above the
float valve. Gasoline has less than half the specific gravity of water,
so the pressure is maybe 1/4 of a pound at the float valve. That's why
the tiny little float has enough bouyancy to close the float valve.

> I say this because I was watching the
> problem persist as I was working on the bike and the leak started at
> the carb and it wasn't until an hour later that a leak started to
> develop from the petcock (not saying the petcock wasn't *leaking* then
> it's just that the pressure built up so much that with the tank
> attached gas was coming out of the seals and overflow screw on the
> petcock.)

It's not the pressure, as I said above, but gasoline is thinner than
water, so it weeps pasts gaskets and goes through tiny gaps in rubber
parts easily.

From: nomorespameventhoughthejapanesespamgivesmeachuckle on

FB wrote:
> nomorespameventhoughthejapanesespamgivesmeachuckle wrote:
>
> > But... I changed out the seat and the needle with known good ones out
> > of a rebuild kit and the problem still persists. Do you disagree that
> > there is definitely a problem with the petcock that it keeps leaking
> > -drip drip drip- when it's in the ON or RES position (it's vacuum
> > operated).
>
> Yes, you might have a problem with the petcock diaphragm, the automatic
> valve operated by the diaphragm, the spring that pushes the valve shut,
> or you might have a bad grommet in the selector side of the petcock
> which allows fuel to leak from the PRI side to the ON port.
>
> The float in the left carb may be set too high, the needle valve could
> be leaking, and there could be trash on the float valve seat that has
> accumulated there since you installed the new seat.
>
> > I'm wondering if the petcock was the
> > original problem or if that became a problem because of another (i.e.
> > pressure built up and the gas had to go somewhere so it put a small
> > hole or tear in the diaphragm).
>
> There just isn't that much fuel pressure in a gravity feed system where
> the highest point in the gasoline level is maybe 12 inches above the
> float valve. Gasoline has less than half the specific gravity of water,
> so the pressure is maybe 1/4 of a pound at the float valve. That's why
> the tiny little float has enough bouyancy to close the float valve.
>
> > I say this because I was watching the
> > problem persist as I was working on the bike and the leak started at
> > the carb and it wasn't until an hour later that a leak started to
> > develop from the petcock (not saying the petcock wasn't *leaking* then
> > it's just that the pressure built up so much that with the tank
> > attached gas was coming out of the seals and overflow screw on the
> > petcock.)
>
> It's not the pressure, as I said above, but gasoline is thinner than
> water, so it weeps pasts gaskets and goes through tiny gaps in rubber
> parts easily.

If it's not pressure, then why does gas not weep through gaskets when
the carbs are presumably flooded? The parts that the gas is weeping
through are exposed to gas even when the carbs are not flooded, though
they weep not then. Thanks for you help!

(Also if you don't mind, privately - or openly, your choice - mail me
how the carbs on my bike work because it seems I might not understand
them correctly.) nousenetspam<removethis>@gmail.com