Hi everyone,

My bobbed Tr1 is almost ready to give it a test run. I overhauld de carbs and now it,s time to put all the hoses back. But now I,m lost. My Tr1 has a different gas tank with only 1 petcock. There is only a fuellhose connected to it which splits to both carbs. The small vacuüm hoses from the front and back intake are also connected to each other with a splitter and go to the mixture control valve from which te large vacuüm hose goes to the front intake. So the small vacuum hoses are not connected to a petcock. Is this a correct way to connect the hoses with this fuelltank setup, and if so can I also cap of the large vacuüm hose like many do. This setup  just don,t seem to make sence to me. Hope someone can help.

Hi, Your setup should work but you can also throw away the mixture control valve and just close the connectors on the intake manifolds. If the petcock just has ON; OFF; RES it does not need a vacuum hose.

Thanks for the reply,

That is indeed the kind of petcock I have. So can I also plug the small lines off the intake manifold or just the big one and connect the small ones to each other?

Both should work. I have just plugged them. Some Yamahas had YICS, Yamaha Induction Control System, which was a connection between the intakes of the cylinders. The XJ models had it and the XZ550 also. If it really has an effect is not conveyed...

Thanks so much for the help. That would clean up my bike a lot. I,ll give it a shot.  ;D :thumb: