Gas Leaking from Gas Cap

[eagle]

Gasoline is leaking from my gas cap on top of the gas tank. It happens when I fill the tank to the top. There is an overflow, but why does the overflow only work once in a while?

Would it just be the rubber gasket requiring replacement or is something else possibly wrong?

[cactusjack]

You aren't supposed to fill it to the top, just to the bottom of the fill tube. Gasoline expands a great deal when it gets hot. It comes out of a cool underground tank into your tank sitting just incheas above a hot engine on a hot day, and presto! It expands and exits through the overflow tube.

Are you filling the tank with the bike on the sidestand? That is the proper way to fill it, and only to the bottom of the fill tube. I usually go a little above the bottom of the fill tube to be consistent.

[macmac]

Never fill over 1/4 inch from that plate! Cj is correct ...

[ringadingh]

I'll fill my tank right to the top only if Im going to be riding it a bit right after I fill it. If you fill it and park the bike you found out what happens.

[Stump]

I foundout that lesson the hard way ,so i only fill my tank all the way when i'am ging for a ride and if i fill it to store it for awhile in the summer i never go over the bottom of the fill tube because of that .

[AlabamaNomadRider]

I think the book says to only fill to the plate in the fill tube. I usually go over it just a bit but never all the way to the top.

[eagle]

I understand the part about the gas expanding and such. I am talking about filling up the tank just past the fill plate with the intention of continuous riding right after filling the tank. I only will do this if I am in an unfamiliar countryside area where I will not know where the next gas station is located.

I do fill the bike while the bike is on the side stand.

It seems like it is normal that gas will leak out of the gas cap area when you fill the tank past the fill plate.

[rewindgy]

Been there done that - there is a small o-ring missing from your bike. There is a small nozzle in the cap that the overflow is supposed to discharge down the drain hole in tha tank. It seems Kawi saved some cash on them and forgot to put in - they are like two bucks. Prt No. 92093-1030 seal, fuel tank cap. If this is not it then the cap is pluggin.

[macmac]

rewindgy, More details please. I am lost.

I know to the right of the filler cap with it open there is a water drain hole for the well around the cap, but the rest has be baffeled.

Eagle does this tank whistle in the heat of the day ever? It should.

[eagle]

Yes Mac, It does whistle. No song in particular though.

[macmac]

ruled the idea out.

[bobhamlin]

Somewhere in the last two years, I posted a call for help on this matter. BD responded that the problem was related to a little plastic diaphragm in the gas cap.

I removed it per his instructions and the leak stopped. I posted close-up photos of the specific parts, but I can't locate them now using this site's search function.

key words are probably: leak diaphragm relief "half moon" or "half-moon"

[rewindgy]

Macmac: yes that drain hole also drains fuel that oveflows. My o-ring was missing and if I put any fuel in over the bottom of the cup it would leak out onto my lap! I went thru the complete gas cap and everything worked properly. So after discovering the missing o-ring - I started to experiment with how full I could fill the tank without it puking on my lap - I can fill it right up to the top - and the gas will only puke out the drain hose - not a drop in my lap! I also now can actually fill the tank almost a complete US gallon more than before. This was my biggest complaint as with the trailer 4.5 US gallons of fuel doesn't go very far - especially in a wind! So now if I do overfill it it leaks just like every new Harley decker does!

[redjay]

Doesnt the vent hose on the Nomad dump the gas out under the bike in front of the back tire ? That would bother me.

[AlabamaNomadRider]

That is where the drain hose is routed, just to the left and front of the rear tire. I have experienced no problem with this. Sometimes if I fill up before I get home I will notice that several drops have dumped at that spot. It doesn't create a problem as far as I can tell.