Fuel gushing from filler cap

[MFA]

Hey guys;

A couple of days ago I filled up the tank as I normally do, but I might have overfilled it a bit. Driving home, fuel started to gush from the fuel cap all over the exhaust, and my pants. I was not far from home, so I stopped the bike a couple of times to let it vent a bit till I got home. Once home, I sucked some of the fuel off and the next morning drove the bike with no issue. Stopped, filled up with gas after ~100 miles, making sure not to overfill, everything seemed fine. On the return trip, stopped again for gas (same station), making sure not to overfill, but this time the fuel started gushing. I did notice the first time this happened, that fine white granules were coming out of the tank. Today I took the tank cap apart and 'cleaned it' but have not had a chance to fill it up again and evaluate.

Any ideas what can be causing this and the remedy?

 

[pica]

If you are not overfilling it, I'll look for vent hoses coming out of the tank, maybe pinched? Not sure if we have those in this bike, but likely

 

[AzRocketman]

Good evening,
I have too experienced a pressurized gas tank, mostly when tank is 1/4 or less. I removed my gas tank to replace the air filter. It would have been easy to have pinched the vent hose going to the charcoal canister.
I might need to remove the tank next time it is empty to check vent hose. (The small hose vertical)

Vent routing diagram below.

 

[MIG]

Definitely sounds like a vent hose issue... As long as ambient heat is not an issue. During the summer I had to put less gas in my '08 America due to the gas expanding and flowing out.
-MIG

 

[stingray]

Make sure to run a flexible wire up into the vent line to ream out spiders wasps and other obstructions that like to crawl in there.

 

[EskimoPie]

I've had this occur a couple of times as well. For me it was always soon after a fill-up on a very hot day so I attributed it to fuel expansion. I try to avoid filling up and then parking the bike in the sun on a hot day. I also started installing the gas-cap and pushing down hard while I'm giving it many clicks to ensure it's fully tight (and also using the key lock that I was just leaving unlocked before). Haven't had the issue in many months now, but it's just starting to get hot again in Arizona so time will tell.

 

[MFA]

Update: I disassembled the gas gap and cleaned it. It had the white residue I mentioned earlier under the white diaphragm. If filled it up (not too much) and tried it again. So far so good.

 

[Mighty Mouse]

If you ride the bike for an hour or so and after you park it take the gas cap off. If the gas shoots out with a lot of pressure then you need a new tank. It happened to me thinking it was the EVAP system but the dealer said it was in fact the tank itself so they replaced it. I had just got the Rocket and it sat in the garage for an hour after a fill up and I wanted to put a little Seafoam in it. Gas shot out of the tank and all over me. The exhaust and headers were cooler but still warm. It could have of been ugly if I took the cap off as soon as I parked it. Just a thought.