Recently bought a 2014 evo 300 and found this in the box of spares. Not sure what it's used for.

Thanks

I'm guessing its the fuel tank vent hose. Being fairly elaborate-looking I'd say that it comes with the bike to enable it to be sold in some countries that require a one-way valve in the vent hose for emissions laws compliance.

Does it have a vacuum operated fuel tap? Some bikes have a fuel tap that opens automatically when the engine is running and this could be the hose for that.

Maybe it's the coolant system vent hose.

Edited August 16, 20188 yr by feetupfun

Yes, I can only blow though one way.

 

This tube and check valve is connected to the exhaust head on the motor side of the catalytic converter that has come with some bikes. I believe the idea is to add fresh air to the exhaust to help promote cleaner air to come out  of the exhaust. The check valve is so that exhaust does not come out of this tube.

2 hours ago, reggie said:

This tube and check valve is connected to the exhaust head on the motor side of the catalytic converter that has come with some bikes. I believe the idea is to add fresh air to the exhaust to help promote cleaner air to come out  of the exhaust. The check valve is so that exhaust does not come out of this tube.

Thanks, so I don't need it then.