Fuel Tank Vent Tube Purpose?
 

I'm new to ATV's, and these may seem like silly questions, but ...

Why does my Honda Rincon ATV have a vent tube coming out of the fuel tank cap?

The non-fuel tank end of the tube goes into the ATV's dashboard ... Why? What does it do there?

I've searched the web using all sorts of different terms - vent, breather, fuel cap, gas cap, ... and I can't find any information about why the tube is there. I even purchased the service manual, but still no clear information there.

I don't find such a tube in any of my other engine-driven vehicles (cars, tractors), so it makes me wonder if its not so much for allowing air to get into the fuel tank (thus reducing the vacuum that might form as fuel is used), but maybe more related to preventing of a fuel spill if the ATV rolls.

Thanks,

Ken

think you answered your own question,my Rancher has one to.

Yep thats exactly why its there.
The tub over it is to really prevent dirt from getting in and if anything comes out it will keep it off your plastic.

Hmmm, so the end of the tube that goes into the dashboard area ... what goes on in there? Is it just a big dust cap? Does it drain into somewhere else? maybe back into the fuel tank?

As you suspect, it is to relieve the vacuum created when fuel is pulled from the tank. using a length of hose helps keep dirt out of the tank. Routing it into the dashboard area is also to keep it dirt free, nothing else is going on in there. In really muddy conditions they can still clog up, but it seems less common on the utes that have better splash coverage. for the record, I have clogged a few on my sport quads...

I believe on cars and trucks the vent part is built into the cap itself. Not sure about Honda but some atvs have a built in rollover valve thats supposed to shut that vent closed if the atv ends up flipping.

Its there to alleviate a vacuum situation - which would cause your ATV to stop running.

My Honda has a metal on/off valve IN the cap. You turn the valve OFF when storing or transporting it but you must turn it ON before riding. If you dont most of the time it will run for about 2 to 3 minutes then die.....and its a MOFO to start again.

The tube, as everyone explained above, is just there to route any spillage away from you and also to keep mud from clogging the vent.

On my kids quads its impossible to keep those tubes in place.....they take off on the track and then after a couple laps, hell the tubes are long gone. Ive tried a couple things but in the end I just decided to leave them off.....no spillage so far and no other issues have came up.

Most cars are a two way system with the vapors routed back to the emissions system from the tank via another fuel line. This is quite different from the single line system on quads.

Vent tube
 

The fuel vent tube for the wifes LTZ250 quad plugs into the dash board, the fuel vent tube on my LTR450 feeds into the top of the front forks under my handle bar.

If you keep loosing the tube make it a little longer and try the same thing as my LTR450 I run it through some pretty rough stuff in the desert and it has never pulled out....yet......anyway

everyone is correct the vent in your fuel tank is so your tank can feed fuel to the engine..plug the tube and the fuel stops feeding.

all the newer cars are pressureised. epa rules now. same thing goes for the changes on the gas cans. as for the newer cars/trucks if you leave your car running while your filling your tank the check engine light will come on as it senses a leak.

the vent tube on the wheeler just goes into the dash and a little bit farther and ends. my kawi had the same thing. my 08 sportsman has it built right into the tank. it goes under the plastic and runs into the steering stem. if i fill it up into the neck on a warm day it will start to spill out and i will smell gas. the tube keeps the gas off the plastic, and the engine. also keeps the inside of the tanks vacume the same pressure the same on the inside and outside to keep the gas flowing freely. or you wont go far as fuel wont get to the carb.

sdhsfnsdgnd

You gotta wonder dont you?

**edited by atv connection moderator**