Fuel Line Routing Question

[JChips]

I'm thinking of setting up my fuel lines so that one petcock goes straight into one of the carb fuel ports and the other petcock goes straight into the other carb fuel port with inline filters on each side. I know some people have done this but with a crossover connection between the two lines so that one petcock can feed all the carbs in case one petcock gets blocked. I'd really like to leave out the crossover for simplicity sake and to allow less kinks in my fuel line routing. I'm wondering what's the worst that could happen if one side (for whatever reason) got stopped up while you were riding. Would it just start running poorly and die or something, or would it cause damage? Thanks

[motoman]

Depending on which model bike you have(Special or Standard) My 81 Venturer(Standard) has the petcocks with the diaphram that fuel flow is shut off when not running, positions on these are ON, PRIME, and RESERVE. Specials use the octypus fitting for petcock lines to do the same thing. By what you intend to do, you must have a Special. Eliminating the octypus fitting in that case could cause fuel leaking by the needle and seat in the carbs, which can cause problems you would'nt like. One clean set-up option is using the petcocks off the Standard tank, which will give you to fuel lines and a vacuum line from carb. manifold to a tee, and to both petcocks. There's several other ways. and maybe some will chime in here.

[fredintoon]

Built in compressor

Hi JC,
I got my Special as a non-runner and the PO had already removed the octopus. I initially just connected the left tap to 1 & 2 carbs and the right tap to 3 & 4. BTW the Special has 2 feeds from each tap. Block off the "prime" connector or the gas will run out onto the street when the tap is turned that way. Once blocked, prime = off.
With this simple hookup, if one side is blocked or simply wasn't turned on you will be running a 550cc 180º vertical twin that's turning a 550cc air compressor as well as dragging the bike along. It won't damage anything but it for sure won't run too good.
Fred Hill, S'toon.

[Ljay40]

Yeah I hear ya on simplicity I just ripped out my octopus and
I had a heck of a time trying to run tee's and a filter to each carb just no dang room on my special especailly if you have stock airbox!
I had bought clear line thinking oh how nice it would be to see the gas but it was not easy as the clear fuel line kinked way to easy,I had found these great little filters at NAPA see through
but seems there is just not enuff room for them with t's sitting above them (well there is I guess cause some guys have done it PITA tho) and trying to get the hoses on the tank and the tank sitting down all the way without kinking I ended up buying the stiffer braided gas line and ran the right side fuel line to the left bank carbs and left fuel line to the right bank of carbs with the small filters, and like Fred says make sure you block off the prime side of your petcocks, mine were the fronts on my special.
1/4 inch for your fuel line 1/4 inch caps for front petcocks and 3/16 cap for your vacum coming from #2 intake mainifold
PS be careful when you pull them 3/16 caps off the intake manifold I pulled the stem right out of mine! Shoulda used a razor knife

[JChips]

Thanks for the help

You guys assumed correctly that I have a special (a 79) and that I ditched the octopus and blocked off the prime. I have those same clear filters from NAPA that you mentioned. Since it sounds like it won't lead to anything serious if one side gets blocked I'm going to go with the super simple straight shot method. Thanks for the advice, it was just what I needed.

[John]

Fuel line routing

Here is how I have mine on both Specials...The left petcock feeds #3 & 4 carbs, and the right one feeds #1 & 2.
If you want an easy way to run one pectcock, but have both available, is to use two T fittings. Now follow closely on this one...Place the two T's so the 'legs' of each T are touching each other, forming an 'H'. Use a short piece of fuel line and connect the two 'legs' together, Now you have an 'H' fitting. Still with me? Good. Now the 'legs' are forming the cross bar of the 'H' right? Here comes the tricky part...Set the 'H' fitting on top of the boots from the airbox to carbs between #2 & 3 carbs. Run some fuel lines from the rear ports of the petcocks to the 'rear legs' of the 'H' fitting. Seeing a pattern here? From the 'front legs' of the 'H' fitting run some fuel lines to the carbs, and cut to length. Now,I will attempt to make a very crude drawing of what I just described.

p/c
l carb inlet T fitting
l l
H fitting
l l
l l
l carb inlet T fitting
p/c

Once you have this plumbed, be sure to cap off the forward (prime)ports of the P/C. They will not be needed or used for any reason. Fuel will flow in either the On or Reserve position now. Are you confused yet? Once you have the plumbing riged, you'll see just how easy this truly is.

[HobbyMan]

A lot of people have done this but you might not want to block off the prime outlet. Several people use this as a way to bypass the filter if it gets clogged. When you are trying to outrun a storm or its late at night, you really don't want to have to stop to clean out a filter or replace it. I still use the octopus. I have not had any trouble with it. The octupus automatically connects both petcocks so you can run from one side if you want to.

[Ljay40]

Hey John

With that set up your using are you running fuel filters ?

[John]

Actually, no, I'm not using any filters. I know the inside of my tanks are rust free, and I have the petcock tower screens plus the screens above the float seats. As far as the H fitting goes, I hadn't used it yet, but I did install it on Foster Child today and it was very easy to install, and it seems to work well. The weather here has been very unco-operative lately so I haven't got any miles on the install yet. Maybe next week end we can road test it. I used to run just one petcock for many years, but, when I had to replace the frame after my accident in '05, I went with the dual petcock setup I described earlier.

[fredintoon]

Your in-tank filters bail out.

Hi John,
yes the XS11 has a fuel gauge or a low fuel warning light, BUT.
This happened on my XS650 which has neither, while the taps are the exact same design as the XS11s:- The combination fuel screen & reserve level devices that live atop the fuel taps fell out and were laying loose in the bottom of the tank. There's no symptom that this has happened on an XS650 until the reserve you thought you had ain't there when you need it. OK, the red light or the gauge on an XS11 will tell you to switch to the reserve setting, so you do that and pull over at the next pump. There is no symptom to tell you that your fuel is now, and has been for who knows how long, been running unfiltered. In-lines is cheap insurance against that.
Fred Hill, S'toon.

[thewiz]

cock fights

This thread is particularly interesting to me right now because I'm currently muddling through my own petcock issues. Now ... no one call the SPCA, OK ? .... I'm not hurting them or letting them fight.

The bike is a 79 Special, which I got mostly in parts and it came with an nice looking octopus but no petcocks. I then obtained a couple of petcocks that are apparently from a Standard because they each have only one fuel and one vacuum feed and say Res On and Prime. Does this sound right so far?

Can I tee the R and L petcock vac ports to a manifold vac source and run separate fuel lines to the 1, 2 pair and 3,4 pair carbs? Would this configuration operate correctly and the fuel shut off when the engine stopped like it's supposed to? I can't even remember exactly how these petcocks are really supposed to be used .... I understand the one petcock soultion offered here too and also that the octupus can still work properly as well. I'm confused. Should I locate the a pair of the Special's own style petcocks and stick the Oct back in or move on with a modified arrangement of some sort? Which of these pet cock arrangements should win out ??? What's the simplist, best solution? Who cares to opine ... ???

[John]

First, the standard petcocks will not fit a special tank. They must be for a special. Then you can lose the octopus, and adopt either method of plumbing in the fuel lines.

[Ljay40]

Hi wiz well I aint no guru so hopefully I wont get kicked to hard
this is my opinion only and the way I understand it to work Hopefully someone correct me if Im wrong. I know what your thinking
Oh great someone who dont know *hit
here goes


the petcocks that you have
should allow gas to flow from them no matter what position there in On,reserve, prime Fuel will flow whichever positon you choose either coming from front outlet of petcock or rear outlet, the front is the reserve I do beleive,attach a hose with a jar under it and then turn on in all three positons and you can see whats exactly going on.
Now vacum supplied to octopus from #2 intake mainfold going to the octopus
will control the opening and closing of the valve in the octopus in the run and reserve position ,and the prime will bybass the octopus and flow strait to your carbs
So in answer to your questions you could still use your octopus with out changing petcocks do a search on octopus and you will find a routing hoses picture to follow if you choose to do that,
If you choose to just run lines to each of the carbs you will have no way of stopping fuel from flowing to your carbs except your float needles which puts a lot of stress on them so to speak
So personally I think it would be easier for now, to run your octopus and then perhaps later change out your petcocks to the
off /run/ prime ones. Its really a personal preference which way you want to go
Please correct me if I'm wrong

[Ljay40]

First, the standard petcocks will not fit a special tank.

See I never thought of that! and John answered while I typed all that out
Too slowwwww

[thewiz]

Thx John

You are completely correct of course, John ... I just tried 'em on the tank and these pets must be Std issue then, cuz they ain't gonna' bolt up lessin' I can find a petcock adapter ... Why should I have thunk they woulda' anyhow .... everything on else on this project has been a PITA. why not the petcocks too. Off in search of a petcock supplier ....

Thx too, Ljay ... due to your explanation, now I think I understand what's s'posed to happen in the different positions.