Petcock dilema

[GuinnessSynd]

So, today I took the XJ11 for a spin before work. 40 miles of awesome riding. Bike is finally inspected, insured and registered. However when I got to work I realized that I did all that riding with the petcocks in the OFF position. Bike didn't hiccup once, The highway part of the trip I was doing 80 the entire way and she was running like a champ. Talking to a friend at work about it and he said I probably need all new petcocks. I am hoping not just because they are expensive. Do you think a rebuild kit would work? Where should I buy them. I am a little wherry buying some generic kits off of Ebay. As always, thank you for the guidance.

[Eveready1100]

Mate, before parting with any money for parts, pull the fuel lines off and check the operation of the taps.
Maybe, a PO has had them apart and put the wrong face plates on and you were actually running on Prime instead of the off position.

[BillyRok]

40 miles with the fuel turned off?? Wow, you are the unofficial MPG champion!!
Whoever tuned your carbs is a real pro!

Here is some info from the FSM, pic 1 shows the petcock parts and ass'y order-

[IMG][/IMG]

Pic 2 shows proper fuel line (fuel pipe in FSM) routing, assuming you still have the vacuum diaphragm (octy) installed-

[IMG][/IMG]

If the petcocks are assembled correctly, the levers point forward for off, down for on, backwards for prime, and up for reserve. Which way were the levers pointing when you took your ride?

The fuel cock levers are marked "L" or "R" so they could be mixed up, and the lever fitting plates could also have been switched. Each petcock has a front and back nipple for connecting fuel lines. With the lever on prime, fuel should run out of the front nipple, through the short fuel line to the "T" fitting which bypasses the octy, and down to the bowls. With the levers on reserve or on, fuel runs out the rear nipple, through the long fuel line to the octy, then back to the "T" and down to the bowls.

I've ordered 2 rebuild kits off Ebay that worked fine. They come with new flange gaskets, fuel cock valve, fuel cock seal, and diaphragm for the octy. It's a K&L kit, #18-5100 I believe. Sometimes you will find the fine screens on the filter towers to be partially plugged with crap from the tank. The plastic fuel cock valves can get worn with small tears or small chunks missing. And the back of the lever that contacts the valve should be sanded smooth with fine grit wet/dry until it's almost like a mirror, put the paper on a flat horizontal surface and use a circular motion with the lever against it. One last thing to be aware of...some have warned that the filter tower can come loose from the petcock and just lay in the bottom of the tank. If that happens, you no longer have on, prime, and reserve...all you have is on with fuel draining from the tank until it's bone dry. But since you can run 40 miles with the petcocks off, you have no worries. Good luck!

[dbeardslee]

I rebuilt the stock vacuum petcocks on my 79F and never could get them to work right. I finally just canned them and replaced them with manual universal petcocks from Partsnmore and never looked back. With the adapter plate and "L" fittings they run $42 ea. at Partsnmore.

The only issue I had with them was using an "L" shaped outlet fitting. I wanted the outlets to point towards the inside to make it easier to get crossed lines on them. Getting them timed right while still being tight was tricky, but I found a fix. I took an aluminum can and cut what amounts to crush washers/shims out of it. It turned out that a cheap paper hole punch was exactly the right size for the outlets, and I just cut the OD's with a pair of scissors. I used five shims on one side and one on the other, and wrapped the threads with teflon tape. End result was perfectly timed outlets and nary a leak.

[Jeffintampa]

Petcocks

How do they work, I just rebuilt mine and have never been real sure does the lever you turn point to the action, or does the top opposite work? and is the off when you put them on go forward on both or back

[DiverRay]

The part you can turn points AWAY from the position. On an F, the long part is down for on, etc.

[johnstewart]

Pic 2 shows proper fuel line (fuel pipe in FSM) routing, assuming you still have the vacuum diaphragm (octy) installed-

So came to this thread looking for petcock advice, and this picture compels me to ask an unrelated question regarding the past paragraph:

"The rear brake and the left-hand front brake are connected to the brake pedal; they are activated at the same time when the brake pedal is applied. The right-hand front brake operates independently; it is activated only by the brake lever. The rear brake and the left-hand front brake provide enough stopping ability for most conditions. However, for maximum stopping ability, apply the right-hand front brake at the same time as the brake pedal is applied."

I've owned 2 XS11's and 1 XS750, and this has certainly NEVER been true. Pedal goes to rear, front brake goes to front, with a split between the two discs in front. They were all '79's; was this something they added in the final years?

I'm shocked to see this!

[bikerphil]

The 81 Midnight Special and 82 XJ11 had that linked brake feature.

[3Phase]

That exact page number 2-14 is out of the XJ1100 FSM and not the XS manual, that's why it mentions the linked brakes.

.

[johnstewart]

Aye! Pretty cool; did that / does that work well?

[3Phase]

Aye! Pretty cool; did that / does that work well?

I've been told that they work but I honestly couldn't tell you, my only XJ was a crashed parts bike and all I have now is a manual and some leftover bitty-parts.

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