Hello all,

Went riding yesterday with my 05 Brute Force 650. Going up a hill i noticed that a strong smell of gasoline was in the air. I looked down just below the instrument cluster and noticed that there was a liquid that had accumulated on the plastic that covers the air cleaner. The engine did not die, I shut it down immediately when I smelled the gasoline. We pulled the plastic on the trail and there was no fuel leak any place on the machine. The fuel tank filler cap was under a great deal of pressure and took about 20 seconds to fully vent. The only thing that I noticed was that under the piece of green plastic that covers the instrument cluster there are four tubes that look like some type of pressure over flow drain tubes. The second one from the left had visible gasoline that had come out from it but after the initial leak nothing else happened. The machine still has the factory warranty and just wanted to know if anyone has had this problem, is it normal, how do I fix it, and does this mean something serious down the road etc. Thanks alot for the help all.

Tim

 

my take here is that you trailered it to where you were riding? did you shut off the gas for trip to the riding area? the sloshing around when it was full could have built up the pressure in the tank. the excess gas could have been forced up through the vent hose? this is the only thing i could could think of.

 

Hey Grizzkiller,
I dont think that is problem because on the Kawi you have two positions as far as fuel goes On and Pri there is no off switch.
oldgrump

 

good call but i'm not sure if he's got the 650 sra or 650I, i'm pretty sure the 650 sra has a fuel shut off just below your leg, at least the prairie 650's do. your right about the 650I and 750 because they dont have a shut off like you said only prime & on. i'm not sure this was the problem just trying eliminate some possibilities.

 

650i and 750 (both IRS) have a vaccum operated fuel petcock - when engine is not running, it automatically shuts OFF. So, in a sense, it has an 'auto' shut off valve - you just don't see it. There are 2 rubber hoses and one metal pick-up tube.
Rubber hose 1- vacuum (from intake)
Rubber hose 2 - fuel output (to carbs)
Metal bube - fuel inlet (from fuel tank)
When engine is not running, there is no vaccum in the intake and it automatically shuts off the fuel petcock.
SRA 650 is manaul fuel petcock - no vacuum hose connected and that's why it has OFF position.

To original poster's problem:
I'm thinking if the one-way check valve on the vent fitting of the fuel tank is not working. He said the fuel tank had a lot of pressure. The check valve should open at around 3~5 psi when the fuel tank pressure goes up. It seems it worked one time because there was fuel in the vent hose which is routed to the front of the handlebar. Then, somehow, it did not work and the pressure kept building up inside the fuel tank. I am thinking the fuel vent check valve got stuck "closed". Another question is why was there excessive pressure inside the fuel tank? Was it a hot day when this happened? Was it a bumpy trail? Was it a long steep hill? Was the fuel tank near full? Any of this can contribute to the problem.
Pressure test the check-valve and see if opens at 3-5 psi - you would need a Mighty-Vac or some kind of hand operated pressure/vacuum gage. Or just tell the dealer what happened and that you need a new check valve. Also, make sure the check valve is installed correctly, directiong wise. The arrow on the valve body MUST point away from the fuel tank - that is the direction of the flow of the excess fuel pressure escaping from the check valve. Another thing you should check is if the vent fitting on top of the fuel tank - just follow the hose from the check valve to the fuel tank - is a thru-hole, NOT plugged up. Disconnect the vent hose
fuel tank and stick in a thin wire somthing like a straightened paper clip. It should go all the way down, at least 4" or more.
Good luck and let us know what you find.

 

all bow down to the mighty Hayashi! well done.

 

Thanks everyone for the great help!!!! Sorry it took me a while to reply but I had computer issues!!!!

To help out it was probably in the low to mid 80's the day we went riding and yes i had just crested a pretty steep long hill climb when i noticed the smell. If i remember correctly the fuel tank was showing about 3 bars of seven still left in the tank. We took off after that and nothing else happened and when we stopped later in the day the tank was not under that much pressure? I actually went to the dealer today and asked and he said that it might be that a piece of contamination got into the carb causing it to overflow out that tube??? Either way we are doing the 10 hour service this week and i will definetly let you all know what we find, hopefully nothing!!! Again thanks alot for all the help.

Tim