Fuel Smell in Cabin

[AXE]

Recently I started smelling fuel in the cabin of the H2 after driving just a short distance. No leaks detected. I've seen some recent posts about the same issue and it seems as though its a pinched vent line, plugged line or bad rollover check valve. Also rollover valve might not be installed correctly.

I ran mine a few miles with the gas cap loosely installed. This seemed to help, but maybe not 100% cause the gas cap vents into the cabin too.

So I decided to pull the seat and center console to check the line and valve. Had to remove the seat and console (see pictures). Line seemed fine no kinks and I pushed some short blips of air through it from the tank end of the hose and could hear it venting.

I haven't pulled the check valve yet, but noticed after another blip of air it did not seem to vent much. Maybe I caused the valve to stick or damaged it even though I was only using <20 psi of air. Anybody know what direction the valve should point (see picture)? I sort of feel like its the right direction, but might be faulty. Might get an aftermarket valve and see what happens.

 

[AXE]

Looks like there is a T in the line before the check valve. It exits via a line under the driver seat, but not sure where it terminates. The line after the check valve follows the shift linkage out the back and comes up the fender well and terminates in a hole in the roll cage frame.

Not sure if the valve is functioning correctly. It is really hard to flow in the direction from the tank vent line to though the check valve, but easy to flow air from the check valve back to the tank. Maybe that's correct, so fuel doesn’t spill upside down and its just letting fresh ait into the tank. If so, then I assume the line before the check valve is letting the tank vent fumes when it's pressured up.

Might have to dig up the service manual or parts diagrams.

 

[olliechristopher]

What about getting rid of the in line check valve altogether and just use a simple roll over vent where it terminates? Way way back in the day that's what we used in our Baja Bug aux tanks. Summit racing sells them as well as any aux fuel tank supplier.

 

[AXE]

According to the parts diagram, the second line ciming off the T before the check valve goes to the other side of the fuel tank. So there are two fuel breather lines off the front corners of the tank.

At this point, all lines seem to be clear and can easily pass air, so I believe this valve is faulty. I cannot push air through it with my lungs. I have to use higher pressure to get it to pass air.

Not sure where the fumes are coming off the tank as all the fittings were very tight. Maybe pushing out the fuel line fitting or pump/filter seal, possibly the gas cap, but it seemed very tight when I unscrewed it.

 

[AXE]

I set my compressor down to 10 psi or so lowest my guage read. I could get a small amount of air to pass through the valve. So it must have operating parameters around that pressure +/-. I know at 20 psi, it moves a lot of air.

So I think one of the steel ball style valves from the KRX aftermarket would be best, but has to be mounted vertically with ball in the down position. That will require realignment of some of the hoses in the OEM location. Or like Ollie said, mount it off the end of the hose where it enters the frame in the vertical position.

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[KawiH2]

RCOR sells a roll over valve. Its a two way valve. It allows air in and out. I dont think the H2 has a way to vent, so this fixes the high pressure problem. It stops fuel in a roll over. Krx has same issue.

 

[AXE]

It's the same as the one I posted from Amazon. I ended up buying mine from ebay for $12.

For 2020 2021 Kawasaki KRX 1000 Oil Fuel Tank Vent, Breather, Rollover Valve US | eBay

For Kawasaki KRX 1000. Rollover Fuel Tank Roll over vent valve. 1PC Rollover Valve. The valve will stop fuel from dumping out. We have professional team to care about every piece of fairing sale from us.

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The problem with the H2 is that the lines are configured differently and it will require modification of the hoses to get that valve mounted vertically. The vent line enters the frame above the drivers side rear wheel well. There is some slack in that line as it comes up from the center of the floor. That might be the best location without hacking up the lines coming into the OEM valve.

In this case, you can remove the OEM valve by the e-brake by discarding the smaller two inch hose and connecting the remaining lines via the t splice that is there. I just bypassed mine for now and well do some testing while my new valve arrives.

 

[AXE]

RCOR sells a roll over valve. Its a two way valve. It allows air in and out. I dont think the H2 has a way to vent, so this fixes the high pressure problem. It stops fuel in a roll over. Krx has same issue.

I've pulled the OEM valve. Like the KRX valve, it it intended to let air into the tank, but keep gas from flowing through it in a rollover. It will allow air to pass out of the tank, but requires a lot more pressure to exit. I believe it's too much pressure to exit easily (especially if faulty) and then the fumes are escaping into the cabin. Not sure why it just started after 700 miles, but it may be that some of them just fail prematurely too.

A other reason theres so much pressure in the tank is that the coolant lines run right below the tank, so your getting a lot of additional heat on the bottom of the tank from 180-200+F coolant flowing back and forth. Gasoline hydrocarbons starts to boil at 100F +/- and continue up to 200F. I think that's partially why I'm seeing this occur as ambient temps have risen as well.