Bike reeks of gas after running - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
Carbs and Fuel System
From the gas tank to the carbs
All fuel system discussion

 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old 02-19-2018, 09:36 PM Thread Starter
NewB to Vulcans
 
TonyO's Avatar
 
Join Date: May 2016
Location: Orlando, FL
Posts: 184
iTrader: (0)
 
Bike reeks of gas after running

The bike stinks up the garage and then the house after I shut off. My commute is 70 miles with lots of freeway so she is nicely warm.

There are no obvious leaks I can find, not even a damp spot.

Since I have owned her I have rebuilt carbs, replaced the boot clamps, new petcock, new gas lines, new vent lines. She is marbled and the spare vacuum line capped. Gas Cap vents have been cleaned.

I am stumped, thinking of dumping some swimming pool leak finder dye in the tank to see whats turns red.

Any thoughts?

'99 Vulcan "Victoria"
TonyO is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old 02-19-2018, 09:40 PM
Senior Member
 
Join Date: Nov 2015
Location: Pittsburgh, PA
Posts: 979
iTrader: (0)
 
Garage
If you let it sit outside until it cools off and then bring it inside, does it still smell up the place?

1992 US-nonCA * tuxedo mod * r/r relocated

Vulcan slang for newcomers
Service Manual Download
Wiring Diagram + annotations * still undergoing revisions, but still more useful than the generic one. Let me know if you find mistakes or think something additional should be added
Thorn is offline  
post #3 of 8 (permalink) Old 02-20-2018, 01:20 AM
Senior Member
 
Spockster's Avatar
 
Join Date: Nov 2012
Location: WV
Posts: 6,444
iTrader: (5)
   
If it's not just hot as Thorn asked... a hot bike can smell gassy, they get hotter just after shutdown.

Could be the petcock leaking through the vacuum line. Is the vac line wet inside or is the vac port at the petcock wet after sitting? Does the oil get overfull and have a strong gas smell? Does the shifter get sticky at the end of the ride?

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual: http://www.mediafire.com/file/mj7z81..._Catalogue.pdf

Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf
Spockster is offline  
 
post #4 of 8 (permalink) Old 02-20-2018, 07:32 AM
Old Fart
 
Knifemaker's Avatar
 
Join Date: Jun 2004
Location: Catawissa, MO
Posts: 11,575
iTrader: (4)
     
Garage
If it stinks up your house, your garage isn't properly sealed.
Hot bikes /warm weather will make your garage smell like gas. Do as suggested and let the bike cool off before bringing it in the garage.

If You Are Not Sure If I Am Joking or Not....I AM !!Photos:
http://www.flickr.com/photos/knifemaker1954/sets/
Knifemaker is online now  
post #5 of 8 (permalink) Old 02-20-2018, 09:22 AM
Junior Member
 
CKGonzo's Avatar
 
Join Date: Feb 2017
Location: Longmont, CO
Posts: 26
iTrader: (1)
 
Garage
Hi Tony, my current bike does the same thing. I cannot locate any leak or seepage. I had purchased a 1989 VN750 years ago straight off the lot (long since gone), and for some reason I cannot remember it stinking the way my current used 2004 does. The only think I can think of is the venting that comes off the tank when the engine is hot. I have just got into the habit of parking it outside or cracking the garage door a bit for a couple of hours after a ride.

Current: 2004 VN750
Former: 1989 VN750, 1978 Honda CB250
Back in the saddle again after sacrificing my ride for my kids in 1994!
CKGonzo is offline  
post #6 of 8 (permalink) Old 02-20-2018, 06:51 PM
Alpha Geek
 
Hexadecimus's Avatar
 
Join Date: Oct 2013
Location: Midwest USA
Posts: 487
iTrader: (1)
 
If it's fumes venting from heat soak after parking, it'd be worse with an almost empty tank than a full one. It could also be a leaky float valve although I think you'd notice that. Does it run fine? Ever have trouble starting? Gas smell in the oil?

Hexadecimus is offline  
post #7 of 8 (permalink) Old 04-18-2018, 08:36 PM Thread Starter
NewB to Vulcans
 
TonyO's Avatar
 
Join Date: May 2016
Location: Orlando, FL
Posts: 184
iTrader: (0)
 
AHA!!

It was quiet in the garage today and I was running in and out a lot fixing an intercom issue . Noticed a hissing noise that i thought was the water softener next to the bike, on closer inspection it was coming from the gas cap. When you get real close the hissing has some bubbling too. Bike was toasty after an hour running in 90 degree weather and gas tank was very warm and more than half full. So I found the source of my gas smell as there is gas around the cap.

Found a bunch of threads related to POOGS fixes discussing issues with the gas cap vent valves getting dirty/stuck/old and stiff (does that sound like someone we know?) so it looks like a gas cap dismantle is in my future.

'99 Vulcan "Victoria"
TonyO is offline  
post #8 of 8 (permalink) Old 04-19-2018, 10:56 AM
Senior Member
 
cglennon's Avatar
 
Join Date: May 2008
Location: Portland, OR
Posts: 731
iTrader: (0)
 
Send a message via Skype™ to cglennon
Quote:
Originally Posted by TonyO View Post
AHA!!

It was quiet in the garage today and I was running in and out a lot fixing an intercom issue . Noticed a hissing noise that i thought was the water softener next to the bike, on closer inspection it was coming from the gas cap. When you get real close the hissing has some bubbling too. Bike was toasty after an hour running in 90 degree weather and gas tank was very warm and more than half full. So I found the source of my gas smell as there is gas around the cap.

Found a bunch of threads related to POOGS fixes discussing issues with the gas cap vent valves getting dirty/stuck/old and stiff (does that sound like someone we know?) so it looks like a gas cap dismantle is in my future.
Hissing from a hot gas tank is normal and means that the pressure relief portion of your gas cap vent is working properly. The hissing is the release of excess air pressure caused by expending fuel (heated by the sun, engine, or fresh gas from a cold underground storage tank). So, this does not sound like POOGS.

POOGS is a situation where the gas cap vent cannot breath (intake) due to blockage. This usually results in a vacuum created as the fuel level drops in the tank and no air can enter the tank to displace the falling fuel level. That vacuum prevents the gravity feed of fuel to the carburetors at approximately 1/2 tank, engines starve for fuel, stall. Open gas cap, relieve vacuum, close gas cap, repeat.

I would still clean the gas cap as a preventative measure. However, it may not solve your problem as the small amount of vapor escaping from the tank should not cause enough gas smell that can reach throughout your house, unless the bike never cools down and the fuel continues to be heated and vaporized (e.g., parked in the sun). There is a small silicone valve on the exhaust port of the gas cap vent that you can verify is still soft and functioning (follow the gas cap vent channel to the very end), but the port it closes off when there is no pressure in the tank is tiny (hence the hissing).

Another option is to park the bike outdoors, in a shaded area, until it cools completely, then move it into the garage. If you still smell gas, then you have a problem other than POOGS (after verifying the silicone gas cap valve is intact). Also, send your wife out to walk around the garage. Women generally have a greater sense of smell than men. She might be able to pinpoint the source.


Chris Glennon - Portland, OR
cglennon is offline  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

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

Password:


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

Email Address:
OR

Log-in










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