Petcock valve mod - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
Carbs and Fuel System
From the gas tank to the carbs
All fuel system discussion

  • 1 Post By lugnut1009
  • 1 Post By Spockster
LinkBack Thread Tools Display Modes
post #1 of 2 (permalink) Old 03-20-2018, 07:11 AM Thread Starter
Senior Member
lugnut1009's Avatar
Join Date: Feb 2018
Location: Mississippi, USA
Posts: 141
iTrader: (0)
Petcock valve mod

I did this mod because I was tired of the old valve leaking and filling my crank case up with gas, also the rebuild kits and replacement valves are so expensive. This does not do anything to the sealing part of the petcock, mine was working well, this only deletes the vacuum portion of the petcock that is so prone to failing and either not allowing fuel to the carbs or leaking through and filing the crank case up with gas.

I can't tell you where to find the material, I was lucky enough to find some scrap pieces at work and use that. I used a piece of about 3/16" thick rubber gasket material. I would think you could use anything as long as it is resistant to gas. You may even be able to do this without it and just seal the 2 pieces with ultra black RTV sealant, I don't know just sharing what I did. Also you will need a M6 bolt/screw to plug the vacuum port.

1. After the petcock is removed (actually did one with the valve on the tank turned on it's side) remove the 4 phillips head screws from the vacuum diaphragm side of the petcock.
2. Completely remove the vacuum diaphragm and spring assembly.
3. While the back cover is off, using an 8mm wrench, remove the brass hose nipple careful not to lose the tiny check valve that is inside. Replace the nipple with the M6 bolt.
4. I used the back plate as a template and cut a square out of my rubber gasket material, marked my holes, and drilled them out. Doesn't have to be pretty, you can trim it later.
5. Lastly just assemble the valve back together with the gasket you just made, tightening the phillips head screws in a criss cross pattern so it seats evenly.

I didn't take any pictures in the process, but here is a picture of the finished product as well as the parts used because I made extra to do another valve at home. This is a quick and easy solution to these problematic valves. Hope this helps someone else. This is the valve from my 85, with red primer over spray.

Petcock by lugnut1009, on Flickr
Spockster likes this.

-2016 Indian Springfield
Chieftain bars
Roadmaster heated seat

-1999 Kawasaki Vulcan 750
Ear shaved
Mufflers removed / 38/140 + 2 shims
Relay coil mod
Pick-up coil mod
Emissions removed
Lowered rear
Rear blinkers located in tail light housing
Petcock gutted

- Wife's: 2018 Can-am Spyder F3 Limited Pearl White
lugnut1009 is offline  
Sponsored Links
post #2 of 2 (permalink) Old 03-20-2018, 10:30 AM
Senior Member
Spockster's Avatar
Join Date: Nov 2012
Location: WV
Posts: 6,872
iTrader: (5)
+1 vote for sticky post!
lugnut1009 likes this.

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual:

Owner's Manual:
Spockster is offline  
Sponsored Links


Quick Reply

Register Now

In order to be able to post messages on the Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Once registered, your User Name"cannot be changed". We can make exceptions within 7 days, but after that, it is set in stone.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome