petcock

[oldyam80sg]

I was curious-We talk about our petcocks and there are 2 on the bike but can 1 be used for everything?I was wondering because my SG's tank is small and have seen other tanks out there with 1 petcock and they are a lot bigger.I don't know what else would fit but is the petcock setup that big of an issue?I look at my ZRX's fuel tank and it has 1 petcock and holds 5 + gallons.

[natemoen]

yes 1 can provide plenty of gas for all carbs but reserve capacity will be cut at least in half.

[cywelchjr]

Yeah, the problem is that on reserve the petcock is drawing from a level below the level of the tunnel hump. This means you are only drawing from one side of the tank on reserve. My honda CL had a cross connect line between the two sides to handle that by keeping them connected so that only a single petcock was needed. My XS400 does it by the back of the tank being low enough to acomplish the same thing.

[11Rider]

Does each petcock supply fuel to all four carbs? I notice on mine there are two fuel inlets - one between carbs 1 and 2 and one between carbs 3 and 4. I don't see any way carbs 1 and 2 share fuel with 3 and 4. Just wondering.

[bikerphil]

One petcock supplies two carbs, it is supposed to be hooked up that way. On my 79 Standard, the left petcock supplies all 4 carbs, but that is my own doing.

[cywelchjr]

On the specials with the octy still in place either petcock will supply both carbs. Without the octy on the special or with a standard the system is each petcock supplies only a pair of carbs unless you setup some sort of cross feed system.

[11Rider]

Oh, gotcha. Thank you.

[oldyam80sg]

OK but was wondering if i was to get a large capacity tank and hook up to my XS would i run into any issues with it beside fitment issues?

[natemoen]

Nope, one petcock is enough, and if it is a tank designed to only use one petcock you are all good.

I do sort of want to set mine up so I can use one petcock, just so that I don't have.to switch both to reserve immediately.

[Ken Talbot]

OK but was wondering if i was to get a large capacity tank and hook up to my XS would i run into any issues with it beside fitment issues?

In the past, I have run my bikes from a small plastic lawnmower tank for the 15 minute ride to or from what used to be their winter storage location. A single feed, split with a T so you feed both sides will work fine, and it does not have to be some large diameter feed feed line.

[fredintoon]

I was curious-We talk about our petcocks and there are 2 on the bike but can 1 be used for everything?I was wondering because my SG's tank is small and have seen other tanks out there with 1 petcock and they are a lot bigger.I don't know what else would fit but is the petcock setup that big of an issue?I look at my ZRX's fuel tank and it has 1 petcock and holds 5 + gallons.

Hi Oldyam,
the flow through a single petcock will be more than enough to run all 4 carbs and a simple plastic tee will split the flow to feed both gas intakes.
FYI, a Standard or a Venture tank will drop right onto the Special frame. There's minor fiddles to the gas level sender and you may have to doctor the seat, the tank swap is well documented on the site.

[oldyam80sg]

OK Fred-I was looking at E-Bay and because i have a Kawasaki ZRX the bottom of the tank has an identical bottom to the XS special tank.I have to take my ZRX tank off to do some things and will start to measure.