gas tank / petcock

[cwieland]

I have a '90 600 Kat I am working on and I have a couple questions. I think I'm having fuel delivery issues on start up. Should the Prime mode deliver as much fuel as normally through the vacumn operated normal and reserve? Has anyone actually taken the petcock apart. I am not able to find parts for it and it's kind of pricey. I think it may be gummed up. I have taken it out of the tank and what I can see looks ok.

Also, there is a nipple (like a vacumn line connection) on the fuel level sensor. Does anyone know where this goes and what it's for. There is no evidence of where it may have been connected.

thanks for any help
con

[brentwoodkris]

Yes the PRIME is just full open all the time. In the ON position, the vacuum generated by the compression of the rising/falling pistons pulls the petcock to the same full open position.

If you're having problems with your petcock, rebuild kits are relatively cheap. I'm sure a member on here could link you to where to find them.

To answer your second question, that nipple connection underneath the tank should be for one of the drainage tubes for gas overflow from what I can remember.

[SerialBanger]

brentwoodkris hit the nail on the head... as for the rebuild kit you can check out ebay and type in katana petcock kit and find some for around 20 bucks if im not mistaken... That is where i got mine from and it was great.. As for your petcock... It should have 2 fuel lines leaving it i believe for the pre's as well as the vacuum hose in the back of it. If fuel flows in the "on" or "res" positions without vacuum applied then u need a rebuild... As for the "pri" position... that should only be used when your bike sits for a couple days and the fuel in the bowls evaporates so you can refill the bowls with fuel. The nipple on the bottom of the tank is for fuel overflow like brentwoodkris said... If you fill up your tank and let it sit in the hot sun it could overflow and instead of leaking all over your tank it goes into the drainage tube and right out under the bike somewhere near the brake side peg.

If you have any further questions there is an article in the wiki i believe and a couple of threads on petcock rebuilds...

Here are a couple...

http://katriders.com/vb/showthread.php?t=96553

http://katriders.com/wiki/index.php5?title=Petcock

[jiver06]

What makes you think your having a fuel delivery problem is it running strange, lack of power, stalling? These can all be caused by similar and unsimilar things. Petcock problem, carb problems, air intake problems. I have a 91 600 and have been over the whole bike. You learn a lot when you diagnose a bike front to back.

Good luck

What makes you think your having a fuel delivery problem is it running strange, lack of power, stalling? These can all be caused by similar and unsimilar things. Petcock problem, carb problems, air intake problems. I have a 91 600 and have been over the whole bike. You learn a lot when you diagnose a bike front to back.

Good luck

What makes you think your having a fuel delivery problem is it running strange, lack of power, stalling? These can all be caused by similar and unsimilar things. Petcock problem, carb problems, air intake problems. I have a 91 600 and have been over the whole bike. You learn a lot when you diagnose a bike front to back.

Good luck

[SerialBanger]

Déjà vu...

[cwieland]

Thanks all. I now understand the fuel delivery/petcock much better now. I mixed some SeaFoam in a couple gallons of gas and ran it through the petcock. My flow now seems much better both on prime which was the original issue and normal and reserve on the vacuum side as well. I will put the tank back on this weekend and , I'm hoping this solves my problems

[brentwoodkris]

Thanks all. I now understand the fuel delivery/petcock much better now. I mixed some SeaFoam in a couple gallons of gas and ran it through the petcock. My flow now seems much better both on prime which was the original issue and normal and reserve on the vacuum side as well. I will put the tank back on this weekend and , I'm hoping this solves my problems

Glad it's taken care of.

[vonrapier]

This could be my small problem with my 1989 600 I put some seafoam in it and the engine ran much better, but then while sitting, had fuel leaking down and out of the tank near the kickstand. I am assuming that this requires a pecock rebuild? dont mean to hijack this thread just wondering why I have the leak now. Could it be the cleaning properties of the seafoam?

[RedKat91]

This was PERFECT.... i have to rebuild the Petcock this weekend... mine was flowing fuel even with the motor off (not in PRIME).

Probably gunked up my number 3 & 4 carb, causing them not to run. And I was firing only on 1 &2.... causing my RPMS to hang at 3k when at a stop because I had to turn the idle screw up to compensate for the inability to run at low RPMs when cold because of the carb issues... caused by the malfunctioning petcock.

We'll see this weekend if it all goes back together properly and all is well! Wish me luck!

[Slofuze]

This could be my small problem with my 1989 600 I put some seafoam in it and the engine ran much better, but then while sitting, had fuel leaking down and out of the tank near the kickstand. I am assuming that this requires a pecock rebuild? dont mean to hijack this thread just wondering why I have the leak now. Could it be the cleaning properties of the seafoam?

First place I'd look for a cheap and easy fix is right at the petcock and check there. I know on my 89 that the hose and clip weren't seated properly after I had the tank off. Let's hope.

[RedKat91]

So question... once you replace the petcock parts, and the carbs (as I have done).... the carbs are now dry internally. How long do I put the petcock switch over to PRIME? Do I just turn it there for a few seconds and then back to "ON" before I fire it up...? Do I have to try to turn it over and fire it up with it switched to PRIME for a second or two and then back to "ON"?