Go Back   DIY Go Kart Forum > Building Plans And Advice > Go Kart Discussion


Thread Tools Display Modes
Old 08-06-2019, 10:20 AM
vybrano vybrano is offline
Join Date: Mar 2019
Posts: 52
Thanks: 20
Thanked 4 Times in 4 Posts
Default How does vented gas cap works; should it smell?

Working today around my ride I noticed, that if you put your nose 7inch/15cm from my gas cap, you can strongly smell fuel.

There's also some mechanism in the cap - probably ball that prevents leaks in upside down position? Or is it something more to it? Could it be bad cap that is evaporating my fuel. Or is it completely normal? I understand that it has to vent tank, but still, should I start looking into it or is it normal?

I wouldn't ask - but it is second hand tank and there are signs, that somebody was inside that cap before me (stripped screw head; glue) - which got me thinking why and what was done and how good... .
Attached Thumbnails
Dirt Bike ATV Gas Caps.jpg  
Reply With Quote
Old 08-06-2019, 10:43 AM
mckutzy mckutzy is offline
Senior Member
Join Date: May 2008
Location: bc, canada
Posts: 7,347
Thanks: 812
Thanked 1,753 Times in 1,447 Posts

Ya.. I typically smell fuel when im that close to the tank... you will smell it through the breather...

Some have a ball or membrane/diaphram to allow the air to escape.... But enough of a gap to not air lock the fuel line... or it wouldnt flow into the carb...
10yr+ club..... My current ride- http://www.diygokarts.com/vb/showthread.php?t=5461
Reply With Quote
The Following User Says Thank You to mckutzy For This Useful Post:
vybrano (08-06-2019)
Old 08-06-2019, 08:40 PM
Karttekk Karttekk is offline
Senior Member
Join Date: Jul 2014
Location: Elizabeth, PA
Posts: 583
Thanks: 18
Thanked 139 Times in 119 Posts

As much as a cap costs, why don't you pick up a new one to be sure? If yours was tampered with, who knows if it's working. The caps have to vent so as the fuel is being drawn into the carb air can be drawn in from the cap as a vacuum.
Reply With Quote
Old 08-08-2019, 10:07 AM
JTSpeedDemon's Avatar
JTSpeedDemon JTSpeedDemon is online now
Currently flathead-crazed
Join Date: Jan 2019
Location: Texas
Posts: 1,941
Thanks: 460
Thanked 226 Times in 208 Posts

My kart's gas cap has a screw vent, and the kart usually emanates a gassy smell.
Got me banned from long term garage storage.
Local Bird Engineering Nut
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

All times are GMT -6. The time now is 06:08 AM.