Please please help!!!

[Clerek]

So I was looking and I didn't realize that I was missing one of the fuel shutoff valves!

Can you please take a look at this and tell me which side it is and which side I need?

Also the second set of pictures are a couple of valves that came with the bike. Where do these go, if they even go on the bike? And if not can I just use these instead of the others? Seems like they might work...

Please take a look and reply!!!

Thanks

-Rick

[Korr]

Hi Rick For sure the fifth picture, that is the left side fuel petcock. The PRI posistion should always be facing towards the back of the bike. The first one i have no ida what side that is and even if it's for your bike. Oh erm...what model is your bike? That last one looks like an aftermarket petcock.

[Clerek]

Thanks!

They are just a bunch of pictures of two different one's...

Can I use the aftermarket one's for the fuel?

I have a 1979 XS1100 Standard

-Rick

[tarzan]

You can use any petcock that will bolt on.

[Ivan]

The first petcock is for a standard. It has the vacuum valve (same as the octy in the special) in the petcock. Not sure what side it goes on.

The second one is an aftermarket replacement with a plate that has been tapped and drilled to suit. No vacuum valve on that. Not really a big deal, but you'll want to make sure and turn it off after each ride, as it is your only like of defense against a leaking needle and seat in the carbs and a subsequent engine full of gasoline. The vacuum valve is just another fail safe.

[Clerek]

Alright so i CAN use the aftermarket ones...

Is there going to be any kind of difference in power? The amount of fuel going through would be less, and there for (in my mind) would mean less power...

-Rick

[79XS11F]

Picture #1 is indeed a 1978 standard model petcock and it is the back side of the LEFT hand side unit. The VAX line attachment nipple faces forward when it is mounted. That's the nipple that's higher up on the unit. A vac hose from carb boot #2 goes onto that nipple
Rob

[dbeardslee]

Clerek - I've got aftermarket petcocks on mine, and they work fine - better than the originals in a lot of ways. Fuel flow isn't any different, unless you forget to turn them 'on' .

[DGXSER]

Clerek,

Doug hit in right, I can not see the difference in the fuel flow capabilities showing up at your carbs. Remember, these are gravity flow, and once your bowls are full, even at redline RPMs I doubt your flowing more than 1/2 the capabilities of the petcocks and fuel lines even when the tank is realatively close to empty. So the smaller petcock opening should not effect performance oen bit.

And thanks for the pictures, I have never owned a Standard so I had not seen a standard petcock. I learned something already today, what one of those look like!

[oldyam80sg]

Not to hijack this thread but got a set of petcocks that go on an 80 SG-don't know what others they will fit but i don't need them.Sure looks different the petcocks for a standard than a special.I run Pingel petcocks on mine and love them.

[Flatlander]

Alright so i CAN use the aftermarket ones...

Is there going to be any kind of difference in power? The amount of fuel going through would be less, and there for (in my mind) would mean less power...

-Rick

Might have a problem if your getting less than, lets say 10 mpg and doing 5 mile drag runs???
If you are really worried, run an equal lenght tube, like the one from the tank to the carbs, to a gas can, turn on one pet cock and time one gallon into the can. Divide that time by two, and if your bike went through more gas than that in that amount of time, then you got too small of pet cocks. This would help too to see if the filters that some have installed is too restricted also??? This is all based on an "average", but I do believe that if you are flowing at least more that twice the amount than the "average" needed amount, that there is enough in the bowls and lines to compensate for short WOT blurps.

My question is: if the type of shut off valve that use the vacuum to allow flow is used.......what's the "real" flow rate under operation? I don't know that question, (can't hold the gas can and drive at the same timeJK) but I have ran my bike with the setting on "on" and "prime" have have not noticed a differance...????

[Clerek]

So this is the setup out of the manual on the right and the setup I'm going to use on the left. Let me know if this would work like this.

(If you click on it it is a little bigger )

[DGXSER]

Well, those are both the setups for the Special model with the "Octy", not the standard. For your bike, take the bottom outlet to the fuel inlet T between carbs 1 and 2 and the other petcock to the fuel inlet T between carbs 3 and 4. The fuel inlet T is the lower one, the upper T between the carbs is a vent. The vacuum inlet on the side of the petcock goes to oen of the vacuum fittings on the intake boots at the head. The ones you use to synch up the bike. It is typically recommended to install an inline filter in the fuel line to the carbs. There are as many ways to route the fuel line as you can imagine. Many have been done very successfully. One way or another, you need to get the bottom outlet piped to the Ts on the carbs, and the side piped to the vacuum source.

[tarzan]

It would work if you had an octopus,but on a standard you dont have one.
The octopus is the thing at the bottom.