Corrugated vacuum hose

[TR5TRIDER]

I am reassembling a 2000 fuel injected Tiger that is a non runner, so as to get it running again. Shop manual is due to arrive end of this week. I am trying to connect fuel system, etc. There is, on the right side of the bike, a long corrugated hose running from air box to ECU? at rear of bike. and presently connected to nothing at either end. Can anyone tell me, what is it for and what does it connect to?
There is a short length (1") of rubber tubing emerging from ECU? located at rear of bike and under seat. What is that for and does it connect to something?

[John Stenhouse]

Should have a pipe to connect the airbox to the ECU to sense atmospheric pressure to compensate for altitude

[TR5TRIDER]

Thank you for the help, I now have one more piece of this puzzle fitted.

[Bixxer Bob]

And take care that there are no leaks (and don't blow down the tube to the ECU, the sensor is just that, sensitive.  Sucking is alright).  Then check where the elbow goes into the airbox, the grommet on the elbow wears and makes a sloppy fit.  It should be airtight so that the ECU accurately reads the depression in the airbox so that, after comparing the throttle position and the pressure in the airbox, it can work out the engine load and select the correct part of the fuel map. Same goes for the breather tube.

If the airbox has leaks on the throttle body side you don't get the correct depression when the throttle is opened so -although the TPS says the throttle is open- the ECU thinks the load is light (such as cruising on a steady throttle) because there is little depression in the airbox and uses the wrong part of the map - which will usually be leaner than it should be.

[TR5TRIDER]

When I bought this bike I had no idea that we would become so intimate! You say "It's OK to suck but not to blow" seriously, what does the breather hose connect to? Is it also corrugated? I have another small piece of the corrugated (approx. 5" length) that still needs fitting. I see in micro fiche that the breather hose is on the left side of air box. I am not seeing any obvious connection places.
Also, in reconnecting fuel line quick connects which hose to which port? Seems it would work either way connected except for direction of flow and considering the filter it might be important not to reverse the flow. My question is which port (upper & lower) is return and supply?

[John Stenhouse]

The fuel lines work either way round, unless one way kinks the pipe, then it's the other way.

[Bixxer Bob]

The small hose coming out of the right side rear of the airbox and disappearing under the seat goes to the ECU at the back under the pillion seat.  Inside the ECU is the barometric sensor, or air pressure sensor if you prefer.  It is very sensitive and so one should not blow down the tube connecting to it for fear of damaging it. 

The much larger hose underneath the airbox on the right is the oil breather.

The pipe on the front left is the drain hose.  If you don't have a spigot on the front left of the airbox, or it's blanked off, you have a later model airbox.

As for the two fuel hoses, I only have one so can't help with that.

[Chris Canning]

[TR5TRIDER]

Many thanks to BB,CC & JS for all the kind help. My Girly is now running well thanks to your help. Have been piling on some miles and the weather has been cooperating. Feeling a bit guilty as I have been neglecting the Steamer that's needing fork seals and my Sprint which only needs riding. 

TR5TRider

[John Stenhouse]

Sell the others you don't need em any more  :icon_wink:  Glad it's sorted!