Petcock valve repair problem

I have a 83 xj-900. I had a peacock valve that didn't shut off as it should in the On or Reserve positions. I bought a rebuild kit and when I took the valve apart to install I found a piece of orange flake something stuck in the center so I replaced the diaphram and the o-rings and put it back together. It still leaks through no matter what position I set it on. I thought with the new diaphram that it isn't supposed to allow fuel flow in on or reserve. Any ideas why? Thanks

 

A couple of things...

If it is a K&L kit, it is probably gonna leak. It is a rarity that a K&L kit doesn't leak!

There may be debris in your tank that may be making it through the screens in the petcock, inside the tank, holding open the vacuum diaphram.

The tank may have sealed itself OK, but your float valves, in the carbs, may be leaking, sticking, etc.

Are you testing it all hooked up, or are you testing the tank off of the bike?

I fixed my leakng petcock with a new petcock!

 

Skippy, yea it's a K&L... Thanks. I just changed back to the old diaphram that looked good and tried a blow-through test. It seems to have fixed it! Now it looks like I just have to find the screen for the top of the valve that goes into the tank. There was nothing there when I removed the valve. I'm assuming that means I have no reserve function or is that no on function? Anyway on ebay they show different types of screens on different valves anyone have a pic of what mine should look like? Thanks

 

I was talking with Bushy at the weekend & he had the same prob with his 750 petcock.
Here's a pic of the petcock from my '85 900.

 

Thanks wizard! That's what I had in mind. I can't emagine someone removing it and not replacing. Oh well. I'll have to run one down and then I'll also put an inline filter in between the valve and the carbs. When I drained the tank there was all sorts of crud in there that apparently had straight access to the carbs! Thanks for the pic.

 

find your screen!
maybe the 900 is diff but when my screen(filter)
fell off in the tank (xj700n) it gave me a week of trouble
before finally flooding the case.
of course thats how i figured out why the bike kepted
running so crapy. the screan also bumped the wire off my
"low fuel" light. that only required a re- solder to fix.

 

Thanks for the tip. I figured it must of been left off at some prior removal. I didn't hear any rattling when I was shaking the tank to get the rest of the fuel out but I'll relook at that when I get home from work today. I went looking for a replacement on Monday afternoon but apparently the bike shops up here in Washington state take Mondays off. Go figure.

 

yah,the piece on mine was a good 4" long and could have easly gotten jammed at the lower end and not made a sound. the fuel will bypass a cv on possition and just go to prime runnig like crap and drianing gas into the case. that = 3qts new qts to flush out the fuel, 3 more plus new filter
to re-fill. no fun and not cheap lol.