questions about 85 xj700 petcock valve

i have a question about my petcock valve. i just bought this bike and its my first so i am a little bit of a beginner. i know it is manual but i only see one line to hook the fuel line into it on the backside if looking at the knob but when i turn it on no fuel is flowing except on what appears to be another port but minus the brass fitting for the fuel line is it possible that the petcock is manual with a vacuum system and the previous owner when he took the tank off to clean lost the brass connector?

edit: if it is missing the brass connector i have looked inside the slot there is nothing broken inside is it possible to find another rather than replacing the whole assembly?

 

The OEM Petc0ck has two Hose Fittings.
One at the rear. A small fitting for the Vacuum Hose to supply vacuum to the Vacuum Operated Diaphragm Valve.

A larger Fuel Outlet, on the right-hand side which accepts the Fuel Supply Hose.

Normally Fuel does NOT Flow from the Petc0ck unless Vacuum is present at the Vacuum-operated Valve.

Setting the Petc0ck to PRI (Prime) ... bypasses the Vacuum Valve and allows Fuel to flow from the Tank without Vacuum.

 

ok i understand that much but what i am saying is that the main nipple for fuel flow is no longer on the petcock it has either fallen out or broke but upon checking it over it doesnt appear to be broken off inside the petcock so is it possible to buy a replacement nipple or create a replacement as i dont have the funds to buy the oem atm

 

Can you post a couple of pics, that way we can tell you if it's an OEM or a possible aftermarket piece?
Is it the one in this picture?

Canadian 85 Maxim-X parts by maximx@rogers.com, on Flickr

 

Turn it around so we can see the back.

dave

 

Here's kind of a back/forward side shot, it shows the vacuum port on the back though.

Canadian 85 Maxim-X parts by maximx@rogers.com, on Flickr

 

Yes that's what it looks like but the brass nipple on the right side is gone

 

Hmmmm, I know the resident parts "magician" Chacal sells just about every part available and offers help with stuff that's not. That looks like part of a complete assembly though and even if you found one I'm not sure it could be installed with any degree of not leaking. Plus I think it's a pressed in piece so doing it yourself might mangle the nipple or damage the body of the petcock.
If there is a replacement and/or a way to do it, someone on here has.
Hang in there!

 

im hoping i can find a decent replacement for my petcock the oem is just to dang expensive at the moment

 

Has anybody had any possible ideas as to what I can do I thought about threading the slot then insert a o ring behind a threaded brass nipple or something along those lines to prevent leakage

 

If that's a New Petc0ck with a missing part, ... return it for a good one.

You might look in the end of the Gas Line. It may have pulled-out.

You could "Harvest" the piece from a Used Petc0ck.

You could fabricate a new outlet.
Copper Tubing.
Make the O-D of the Tubing fit the I-D of the Petc0ck Outlet.

You can gamble on a tight press fit, ... or strip the Petc0ck and SWEAT the Tubing permanently in place with Low-temp Silver Solder.

 

i am attempting to locate a used piece but parts are scarce the bike had no brass piece when i purchased it sadly that wasnt known to me when i checked it over but i am thinking of trying the copper tubbing and silver solder idea tho

 

If/when you try and solder the part, remember to take it apart and take all the "Melty" parts out. :roll: :roll:

 

You won't be able to solder to the petcock body successfully.

Your best bet, seriously, would be to find another petcock on eBay and rebuild that.

You've seen this by now I hope? http://xjbikes.com/Forums/viewtopic/t=25058.html

 

Yes I have seen that but it just shows the normal parts and pieces although I did notice something on there I missed before and that was a threaded brass nipple I found some at advance auto I just need to drill then thread insert a oring and I should be good to go

 

Now here's a question..........there are some of the petcocks that have the fuel-line-out nipple bolted onto the bottom of the petcock. Since I can't see the side where the line usually comes out, is it possible that you inadvertently simply got one of the kinds that needs the 'bolt-on' part on the bottom of the petcock? If you don't know what I mean, let me know and I"ll send a pic of one like that.

Dave F

 

yea i know the type but the one i have is missing the pressed fit style brass nipple so i figured out a fix as advance sell the bolt on fuel brass nipples so i plan on drilling and threading it to attempt to install one i also am gonna go look at a hobby shop to see if maybe they have one that may fit like from a gas rc

 

This will seal it:

http://durafix.com/

 

buy a pingel highflow non vacuum one with yamaha adapter and put a cap on the carb nipple