I have a 2005 636. I purchased it new. Last week I walked into the garage and all I could smell was gas. I then noticed gas came out of the overflow. I opened the tank and gas shot out. There was a lot of pressure. I took the bike to a local non dealer motorcycle shop. He said the overflow is a metal tube that runs through the gas tank to the bottom of the tank where it connects to the rubber house that runs to the ground. The guy thinks the metal overflow tube that runs through the tank has a hole in it. When you look at the underside of the tank there is a little rust around some of the welds and also on the metal lip around the top of the tank. All of which is very concerning to me. I always keep it full to keep moisture from building up in the tank. Needless to say I am pretty disappointed. This bike has 7000 miles and has never been in the rain (Not that rain would cause this to rust.) I keep it in my garage year round. I guess my questions are the following.

1.) Has anyone ever heard of this before?
2.) Is the overflow line metal and does it run through the tank?
3.) Anyone know any places to get a new tank from?
4.) What causes it?

Thanks
Nick

 

This is the 2nd or 3rd post about this problem. I've never experienced it on my old 9. If there was a "lot of pressure" I wondering if the tank vent near/in the cap is getting plugged (sometimes they do; I HAVE had this problem, but only once.) If it's been hot where you live, the fuel may want to expand and head toward the overflow tube if the vapor can't get out the vent.
Sounds like it might be a poor design (since the topic has occurred a few times.)
Anybody else (on here) have a suggestion??

 

I live in upstate NY so it hasn't been really hot yet. I have been wreaking my brain trying to figure out what could have caused this. I know currently there is nothing in the line. A zip tie went down the overflow and came out the other end. The hole in the line make sense because it leaks gas from the overflow even when there is no gas in the overflow on top. The only thing that make sense to me is at some point the line got pinched off. Air flow was not correct and moisture built up on the inside of that overflow line and started to rust from the inside out. But the line looks fine. There is no damage to it. Even if I replace the tank I don't know how to keep this from happening again. I am half tempted to trade it in and get a new one. lol