gas cap leak

Anyone had problem with th 05' WR450 leaking gas from around the gas cap? I have tried turning it extra tight, running with less fuel, and swapping the gas cap from my WR250 but all of these have resulted with gas leaking down the sides of my tank from underneath the cap.

Maybe try a new O-Ring? The KTM has the same problem you said when ever I take it out it leaks around the cap. Steve.

Make sure your rubber seal is still there (not an o-ring) , mine fell out but I saw and put it back in.

When this happens it is usually because the rubber valve under the cap is not seated all the way up under the cap and therefore you tighten it down without a full seal around the cap. :)

Also make sure your vent hose is working, I had one of those goofy billet vent caps that went south on me and stopped breathing.

Explain this one to me...the vent hose has an arrow pointing towards the tank. I took the hose apart and blew air through it. The air only flows in the direction of the arrow. This means the vent hose only allows air into the tank, instead of out of the tank. Isn't the vent suppose to let air out? I switched mine around backwards and i am curious to see if gas leaks during tomorrow's ride.

Explain this one to me...the vent hose has an arrow pointing towards the tank. I took the hose apart and blew air through it. The air only flows in the direction of the arrow. This means the vent hose only allows air into the tank, instead of out of the tank. Isn't the vent suppose to let air out? I switched mine around backwards and i am curious to see if gas leaks during tomorrow's ride.

As gas goes away air has to be able to get in to replace the void left behind. If you reverse it your bike will act like it's running out of gas at WOT. :)

Correct! You will create enough vacuum that the gas will not flow to the carb! :)

Explain this one to me...the vent hose has an arrow pointing towards the tank. I took the hose apart and blew air through it. The air only flows in the direction of the arrow. This means the vent hose only allows air into the tank, instead of out of the tank. Isn't the vent suppose to let air out? I switched mine around backwards and i am curious to see if gas leaks during tomorrow's ride.

Mate. you ride your bike, fuel level goes down. In order to avoid creating a vacuum in your tank, air needs to be drawn in.

When you fill your tank obviously the cap is off and air is purged out as the fuel level rises.

You should be able to blow air into your tank via your pipe/valve assy. :)

You may experience some fuel starvation on your rideout if you leave it 'as is'.....

Makes sense. I will switch it back.

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