Don't Like Interstate

[trout dude]

Ok I need some help. I changed out the motor on Shelia's bike due to an oil pressure issue. The bike runs great around town but when I put it on the interstate running it at 75 to 80 within 5 miles it act's like it's running out of fuel. When I changed the motor I moved all the de-smog kit from the old motor to this one(only had 500 miles on the kit). New gas line with no dips and new thick wall vacuum hose for petcock. What am I missing.
 Dennis

[Louis Durocher]

check the small hose in the back of the tank( this is a vent) Maybe it is kinked .What it does is that after a few miles there is a vacuum created in the fuel tank.Remember that you don't have a fuel pump.When it runs out of fuel try to open the gas cap to see if it will run well again. If it is then you know your vent is blocked.

[CISE]

I had an issue with my '99 I/S. When I was on the highway and the engine area got warm I started to suffer from fuel starvation issues. When the bike cooled down a bit, everything worked ok.

Turned out that the fuel hose from the petcock to the Carb T feed was about 2" too long and would soften up enough when warm to cause a bend to form that blocked fuel flow.