I searched the forums and google and can't find a definitive answer.

If I'm replacing the gas cap with an aftermarket one, should I get vented or non-vented? Bike is in California if that makes a difference

thanks in advance

 

Shouldn't matter. Notice that little piece of tubing under the fill cap? It's a built in overflow/vent line that runs out the bottom of the tank.

 

I thought the 48 was fuel injected and thinking that, I thought the tank was pressurized. So, wouldn't a vented gas cap defeat the purpose of the pressurized tank. I had vents on my dirt bike tanks becuase they were carb'd engins and the vent allowed air into the tank to assist in pushing the gas out when the bike was leaning over or going over rough terrain.

I am really interested to know the answer to this question.

 

I think it should be non-vented but as you can see, it's almost like nobody REALLY knows the answer haha

 

It is definitely vented! You will get vapor lock if you fit non vented. Easy way to tell...lift your full tank up vertically, fuel will gush out at the filler (ask me how I know).

If it was non vented it would be sealed tight.

Check my gas cap in my profile pic, it has a vent in the middle.

The little tube you see in your filler IS an overflow tube. fuel runs down it if you overfill or if you spill any while riding (because you overfilled it). It runs inside the tank and comes out at the back left side of the tank.



In some states the fuel is collected in a type of tray/reservoir I guess. Other models just drips it down somewhere on the frame (follow the little tube on the left side at the back of your tank).

My overflow tube is sealed shut and the rubber boot just slides over it. Bike runs fine because the cap is vented.

 

You can buy either vented or non-vented. The tank is vented in the filler neck not the cap. If you buy a non-vented cap, the tank will vent fine just like it did with stock cap. If you buy a vented cap, the tank will vent fine out the original vent in the filler neck and it will vent through the cap as well. Doesn’t matter how much venting you have. The tank isn’t pressurized, the fuel line coming out is via the fuel pump inside but the tank itself is not pressurized.

 

I didn't know that the filler is vented. As long as the pump isn't sucking against a vacuum you'll be fine.

 

When I bought mine, I went vented just because I wanted it to have plenty of air to be able to breath.

 

Thanks guys. What exactly is the purpose of letting the tank breathe? doesnt this cause the gas to evaporate?

Yes, I am that ignorant

 

EFI fuel tank pressurized?! Oh my ...