79f petcock positions

[mason79]

i took it apart it has less than 4000 miles on it as per invoice from p o.

is there a midpoint position that closes of the flow completely?

help!!

[Incubus]

There is no shut off and it is for this reason that I hate my petcocks. When they leak, they leak sneaky. I hate sneaky.

There is hope. Take them apart, clean them out, do the stuff it tells you to do here:

http://www.xs11.com/forum/showthread...=&threadid=142

My petcocks leaked, but I had the lucky leak and instead of getting into the oil the gas leaked back through the air filter onto my garage floor. Hell of a mess, but my oil was OK. I rebuilt them and still had to do the washer thing to keep them from leaking. Now they are seemingly fine.

Try just smelling your oil. You shouldn't smell any gas fumes coming from it. If you do, change it and fix the petcocks. It's a pain, but consider the alternative.

Patrick

[mason79]

yes i smell it for gas

i feel it for viscosity.

i light it to burn, but i'm still unsure, as the oil has 0 miles cause i just changed it...


yes i read the link and i will reread it, it's about time to learn about petcocks the hard way... thanks boss.

[mason79]

here are some other general petcock questions i have,

1/ i have read that the mighty xs1100 can perform with one gas feed, but will it handle a big bore or other mods?

2/ if i go to one feed will it be nessesary to balance the 2 sides of the tank? will all the gas flow without this assistance from one side to the next without compromise?

3/ i have not looked an new bikes, is the vacuum configuration still in use?

4/ if so is it one or 2 petcocks? sportbikes? 1800cc cruisers?


5/ in our vintage era, which large displacement motorcycle utilized only one petcock?

6/ our vacuum petcocks are fussy and delicate (lame)

7/ will manual petcock with it's constant manual minipulation, fail sooner than a vacuum with automatic minipultion?

8/ how many posts does a member really need to be able to get all these question right?

[TopCatGr58]

Originally posted by mason79
here are some other general petcock questions i have,

1/ i have read that the mighty xs1100 can perform with one gas feed, but will it handle a big bore or other mods?

Yes, one petcock can feed the fuel much faster than the carbs and engine can empty!

2/ if i go to one feed will it be nessesary to balance the 2 sides of the tank? will all the gas flow without this assistance from one side to the next without compromise?

The tank tunnel prevents "some" of the fuel from being shared between the non petcocked side and the petcocked side once the fuel gets fairly low. This could diminish your reserve range a bit, but shouldn't otherwise cause any problems.

3/ i have not looked an new bikes, is the vacuum configuration still in use?

Road Star uses one petcock, gravity. The FJ1300 and Vmax use fuel pumps! The Vmax has a separate tank vent vs. the gas cap!

4/ if so is it one or 2 petcocks? sportbikes? 1800cc cruisers?
see above
5/ in our vintage era, which large displacement motorcycle utilized only one petcock?


6/ our vacuum petcocks are fussy and delicate (lame)
That's why I like the gravity ones of the Special.

7/ will manual petcock with it's constant manual minipulation, fail sooner than a vacuum with automatic minipultion?
The vacuum controlled petcock has both the vacuum diaphragm/plunger, along with the petcock valve and associated rubber parts. The gravity petcocks just have the valve, again with associated rubber parts, gaskets, but I would think the vacuum style would be more prone to premature failure!

8/ how many posts does a member really need to be able to get all these question right?

Did you mean to get them answered? Possibly 1 or 2?
T.C.

[mason79]

thanks topcat, does that mean the specials has to be manuallly turned off?

[Incubus]

It means the special petcocks CAN be turned off. Your float valves will, in theory, shut off the fuel flow if you leave the petcocks on. My 1975 Honda 750 has that set up, with a single gravity feed petcock. In real life, the float valves usually do shut off the flow. But it doesn't take much to let them leak. A tiny piece of grit, a not quite right jostle, and they leak. I always turn them off when I park the bike, even for a short stop.

Still, much better than trusting these faithless vacuum petcocks.

Patrick

[DiverRay]

I used a rebuild kit on the "daily ride", and have had NO problems. The thing is to CLEAN the parts you need to reuse, and be sure the petcocks go back together correctly. I DO park on the center stand almost all the time, but that is because of the longer rear shocks. If I use the side stand on the flats, the bike leans WAY over.
Ray

[planedick]

Petcock problems...

I have never had any petcock problems, and I hope I never do. I do put MMO in my gas though and I think it helps lubricate the "O" rings in the selector area and probably helps the vacuum valve work freely too. I remember when gas had lead just to keep things polished and shiney, so now I add MMO to help lubricate valve guides and rings.

[red bandit]

I have had other bikes, along with my 4 wheeler and xs11 in the garage now. I NEVER shut off the gas on any of the 1's I've had or have. If the carbs are working properly they won't leak. Yeah, you can get some dirt in there. Guess I'm just lucky...or stupid!!

[mason79]

Originally posted by red bandit
I have had other bikes, along with my 4 wheeler and xs11 in the garage now. I NEVER shut off the gas on any of the 1's I've had or have. If the carbs are working properly they won't leak. Yeah, you can get some dirt in there. Guess I'm just lucky...or stupid!!

wow, my valves are holding well now.. but i'll get to it...

[mason79]

pics of right petcock



the po had the dealer put new ones in, this is the right one, but the outlet is the same as the left one, i don't know if yamaha put 2 left one on the bike it seems that way because the outlet pointing to the back would clear the carbs a little better.

??just want to know if you guys can tell if these are stock items, before i buy rebuild kits.


?? i saw the invoice for these they have 3400 miles on them should they leak so soon, is there a spring behind the diaphram i cluld stretch out??

thanks guys!!

[DiverRay]

The OEM petcocks have the fuel line connect on the FRONT. there are left and right sides, and they are all that work. The PO of daily ride had two "new" petcocks installed, and they were NOT factory. They hit the airbox, and ended up cracking at the fuel outlet.
The factory ones have the fuel line connect facing to the inside of the bike, on the FRONT of each side. I did put rebuild kits in the factory petcocks I got to replace the bad ones, and they have worked great for the past two years and 38K miles.

[mason79]

okay i took it apart again it leaks to the carbs,

and reading something here,

i thought i saw someting in the vacuum line while running,

and when i took it apart the second time i looked in back of the vacuum diaphram and it had gas in it, plenty of it.

i think the gas was going to the #3 carb boot,

so does that mean the diaphram is shot, cause by looking at it it seems like new, yeah right,

you be the judge you look at above pics.

anyhow, any help would be nice.