Forums 🚥 PIT STOP 🔧 Hyosung Technical Help How to change Vacuum Lines on Hyosung GT125R GT250R & GT Comet (Air Hose Diagram) Reply To: How to change Vacuum Lines on Hyosung GT125R GT250R & GT Comet (Air Hose Diagram)

  • Topics: 0
  • Replies: 3
Aug 5, 2019
2008 GT250R


So I’ve had the carb off of my 2008 GT250R for about 7 months. Having trouble figuring out hose routing for reassembly. The bike fires up just fine without any hoses attached & with the carb exposed & primed. I’m not the first owner so some things appear to have been changed. The 3 valved fuel thingy is confusing and my rear intake manifold boot only has one valve, no two.

Is there anything redundant that I can just bypass? If not, I’m still at a loss for how to hook this up.

I’ve labeled all the existing hoses with colors & letters. The three taps at the gas tank are labeled numerically. Please help.


More descriptions:

A(red): goes from the three valved fuel thingy to the carburetor

B(blue): No idea where this goes? It looks the same size (inner diameter) as what I’m guessing is the fuel tank breather valve (1)

C(green): Small inner diameter tube from rear cylinder manifold boot. **No idea where this goes**

P(pink): Air hose from air box to cylinder pump thingy.

Y(yellow): one line from the three valve fuel pump thingy comes out of this, it’s joined at a T juncture with the vent hose from the front cylinder intake boot valve, and they lead to the back of the cylinder pump thingy.




Side question: Put my fuel tank upside down for 3 minutes and a bunch of fuel leaked out of the fuel cap. There were no gaskets there when I took it apart, and the exploded view online doesn’t seem to have gaskets either. Is it supposed to leak or should I reinforce it? Ruined my brand new paint too. 🙁

Skip to toolbar