From: nomorespameventhoughthejapanesespamgivesmeachuckle on
This is a slight continuation of thread:

Gas Leak on 1982 Yamaha Maxim XJ750J | Petcock and Carb

I thought this warranted a new thread since my questions were answered
in said thread.



I just received the petcock rebuild kit today and went forward to do
so. I had taken apart the petcock before so I knew my way around and
finished with what I thought were no problems. In the kit I received a
new diaphragm, valve switch grommet, and whatever the name is for the
vacuum parts...

I replaced all of these and the only observations were that the old
diaphragm was a little tough to get out. It took some serious but
careful prying to get it out. After getting it out it seems that parts
of it were stuck to the metal and little minute pieces of the diaphragm
were still stuck to the metal after I pullet it out. I carefully
removed the little pieces with a toothbrush, fine-point piece of metal,
and gasoline. Then I rinsed the inside out with fresh gasoline to get
rid of any extra debris and put the new diaphragm in.

So I took the bike for a ride to the gas station, filled it up, and
went for a ride. Then I went home and let the bike sit for about an
hour; I came back out and was not pleasantly surprised.

All *four* carbs were no leaking from every crack imaginable and when I
took off the gas line from the petcock (which was on the on position)
gas basically free-flowed out of it... not drips but free flowed.

This is not good... hopefully I didn't get any gasoline past the
cylinders into the case.

Any ideas on what I did wrong or whats going on? It wasn't too
difficult to rebuild the petcock so I don't know what could have gone
wrong. Did I not push the diaphragm in far enough (should I really
push it on)? Did I mess up something in the vacuum part of the
petcock? Did I tighten screws to tight =)?

Any help is appreciated; I know it's kind of hard without being there
but I need ideas!

From: Wudsracer on
Is there any chance that you got the rubber "valve switch grommet"
turned wrong? Could you possibly have it set in place so that when
you have it in the "on" position, that it is actually in the "prime"
position?





>On 5 Jul 2006 21:05:41 -0700, "nomorespameventhoughthejapanesespamgivesmeachuckle" <nousenetspam(a)gmail.com> wrote:

>This is a slight continuation of thread:
>
>Gas Leak on 1982 Yamaha Maxim XJ750J | Petcock and Carb
>
>I thought this warranted a new thread since my questions were answered
>in said thread.
>
>
>
>I just received the petcock rebuild kit today and went forward to do
>so. I had taken apart the petcock before so I knew my way around and
>finished with what I thought were no problems. In the kit I received a
>new diaphragm, valve switch grommet, and whatever the name is for the
>vacuum parts...
>
>I replaced all of these and the only observations were that the old
>diaphragm was a little tough to get out. It took some serious but
>careful prying to get it out. After getting it out it seems that parts
>of it were stuck to the metal and little minute pieces of the diaphragm
>were still stuck to the metal after I pullet it out. I carefully
>removed the little pieces with a toothbrush, fine-point piece of metal,
>and gasoline. Then I rinsed the inside out with fresh gasoline to get
>rid of any extra debris and put the new diaphragm in.
>
>So I took the bike for a ride to the gas station, filled it up, and
>went for a ride. Then I went home and let the bike sit for about an
>hour; I came back out and was not pleasantly surprised.
>
>All *four* carbs were no leaking from every crack imaginable and when I
>took off the gas line from the petcock (which was on the on position)
>gas basically free-flowed out of it... not drips but free flowed.
>
>This is not good... hopefully I didn't get any gasoline past the
>cylinders into the case.
>
>Any ideas on what I did wrong or whats going on? It wasn't too
>difficult to rebuild the petcock so I don't know what could have gone
>wrong. Did I not push the diaphragm in far enough (should I really
>push it on)? Did I mess up something in the vacuum part of the
>petcock? Did I tighten screws to tight =)?
>
>Any help is appreciated; I know it's kind of hard without being there
>but I need ideas!

From: sharkey on
nomorespameventhoughthejapanesespamgivesmeachuckle wrote:
>
> All *four* carbs were no leaking from every crack imaginable and when I
> took off the gas line from the petcock (which was on the on position)
> gas basically free-flowed out of it... not drips but free flowed.

Well, that's pretty bad, I grant you ... the lack of vacuum should be
turning the fuel flow off.

But more importantly, why is fuel leaking out of your carbs anyway?
Seems odd to have all four floats sinking/needle valves leaking?

NB: I didn't read the previous thread (yet) ...

-----sharks
From: 2000 Suzuki katana gsx750f, 1984 Honda Magna V45 on
> This is not good... hopefully I didn't get any gasoline past the
> cylinders into the case.

This is a bad thing. You really should check. If the oil level is
high, well, you should drain it and change the filter. It is quite
possible that it leaked around the pistons.

Good luck!

From: nomorespameventhoughthejapanesespamgivesmeachuckle on


>Is there any chance that you got the rubber "valve switch grommet"
>turned wrong? Could you possibly have it set in place so that when
>you have it in the "on" position, that it is actually in the "prime"
>position?

I don't think so but I'll take a look. I'm pretty sure that it can
only go on one way.

>Well, that's pretty bad, I grant you ... the lack of vacuum should be
>turning the fuel flow off.

It should be yes...

>But more importantly, why is fuel leaking out of your carbs anyway?
>Seems odd to have all four floats sinking/needle valves leaking?

Fuel is leaking from the carbs because the vacuum is not operating
which means the petcock is effectively in the prime position. This
would be the same as having just an inline fuel valve with a simple
on/off switch and leaving it in the on position overnight. You too
would wake up in the morning with flooded carbs; it has nothing to do
with the floats or needle valves since the gravity is forcing the fuel
into the carbs whether they are asking for it or not.