Vapor Lock or what?

[jeffro]

Where are the two hoses? I took my tank and air box off on x-mas to replace the fouled plugs. It was a lot eaiser then I thought.

[oldndumb]

The hoses are item 14. The roll-over valve in the tank vent line is item 33. The other hose is the filler neck water drain.
If you remove your tank, and fail to reconnect the hoses, the bike will run but you run the risk of spilling fuel onto your engine and will spill fuel in event of a tip over.

[iceman]

....... here you go jeffro - the 2 vent hoses are just in behind the blue wire.You must have removed them to get your tank off.




following on from OnD said - I understand the main task for the 'rollover valve' is to stop your tank emptying out through the vent pipe if the bike ends up on its side.
Another trick is to ensure that both pipes are clear of your fairing at the bottom - so that petrol doesnt end up on your paintwork.

Grant

[3banger]

It sounds like the rollover valve to me. I had the same problem after I had the tank off. I decided to route the tank vent lines a little differently to tidy thing up and didn’t fully understand the point of the roller over valve. I left it sitting at a 45* angle and it sealed off the vent line, needless to say the bike ran like crap as the tank got low but ran fine one the tank was vented. Once I set the valve back vertical the problem was resolved. If you pull the valve and hose and blow through it and tip the valve you will feel just how sensitive it is and is clearly designed to block flow in both directions if it is tipped even slightly off vertical. I suspect it is also susceptible to failure due to its sensitivity.

If it ever causes me any problem again it will be removed. My dirt bike leaks gas every time it’s in a horizontal position and this is a frequent occurrence; I have yet to burst into flames.

[jeffro]

Originally Posted by iceman

....... here you go jeffro - the 2 vent hoses are just in behind the blue wire.You must have removed them to get your tank off.




following on from OnD said - I understand the main task for the 'rollover valve' is to stop your tank emptying out through the vent pipe if the bike ends up on its side.
Another trick is to ensure that both pipes are clear of your fairing at the bottom - so that petrol doesnt end up on your paintwork.

Grant

Does it matter which hose goes in which slot on the tank ?

[oldndumb]

Of course it matters. I can never remember which one goes where because I put a yellow tywrap on the fuel vent line to easily identify it.

If someone doesn't do a search and direct you to the thread that discusses this, the easiest way to tell them apart is to try blowing into one of the hoses at the tank end. The water drain is always open. The fuel vent line will be closed by the check valve in that direction. Air flow in the fuel vent line is from the bottom of the hose, through the check valve, into the tank to replace displaced fuel.

What is going on Jeffro.....thought you said this stuff was easy?

The fittings on the tank can be identified by putting low air pressure (3 to 5 psi) on either of the orfices.

[CLB]

The front fitting is the tank vent and should connect to the hose with the rollover valve.

The rear is the drain for the fuel cap detent and required no external valve.

[3banger]

OK I just went out and looked, the line with the roll-over valve connects to the nipple closest to the front of the tank. This is the same port that seals into the gas gap when closed. The roll-over valve will allow the flow of air in both directions but stop flow if tipped.

[oldndumb]

Originally Posted by 3banger

OK I just went out and looked, the line with the roll-over valve connects to the nipple closest to the front of the tank. This is the same port that seals into the gas gap when closed. The roll-over valve will allow the flow of air in both directions but stop flow if tipped.

I'm curious. How do you get a flow of air in both directions through a hose connected to a fuel tank.....especially with an inline check valve?

[4N099]

Exploded view drawings aren't always 100% accurate but the majority of them are if done right, if you look at the illustration it will tell you where the hoses go.
If you are still in doubt and one hose connects to the cap drain bind two pipe cleaners together or use a piece of wire and insert it into the cap drain hole, connect the drain pipe to the fitting they are sticking out of on the bottom side and the valved hose fits on the other nipple.