Bike surges on the highway???

[ericox]

ive searched and cant find exactly what im looking for, but here is my question.

When i am at highway speeds (~70mph) the bike tends to loose power in surges. Not like running out of gas, but more like im riding into a head wind in too high of gear (sorry, best description I can think of). I rebuilt the carbs recently, everything is ok there. Could i possibly need to adjust my mixture screws out a bit (currently 1.75 turns out). My air filter hasnt been changed recently, im going to try that first to see if that solves the problem.

Any ideas are greatly appreciated.

82 750T Stock

thanks

[bwringer]

Float height adjustment is critical (half a millimeter makes a difference), and you do have to re-adjust it if you install new needles. Just a thought.

Also, some have had varying success with removing or changing the location of the bowl vent hoses. If air is rushing past the open end of the hose, some strange things can happen.

[ericox]

all my floats are in specs, i made sure of that. There were no needle changes, i replaced the orings and cleaned everything. The bike runs great, just seems to starve on the highway. I think you might be onto my problem, my vent tube is hangin out the side, definately in the wind. Hopefully that is it. I completely forgot about those causing problems.

Thanks

[ericox]

Problem solved...It was the vent tubes. Once I routed them properly it ran fine.

Thanks

[t3rmin]

Float height adjustment is critical (half a millimeter makes a difference), and you do have to re-adjust it if you install new needles. Just a thought.

Also, some have had varying success with removing or changing the location of the bowl vent hoses. If air is rushing past the open end of the hose, some strange things can happen.

Just had a similar problem. For some reason I'd read this thread a while back and luckily it came to mind when I needed it. Just got the 750 running GREAT, got out on the open road for its first long trip (2 hrs of highway riding), and it started bogging in high gear at speed. Pulled over, re-routed the vent hoses -- PROBLEM SOLVED! They were kinda hanging out the sides and very exposed to wind.

Thanks! This advice salvaged a good ride for me today -- I probably would have turned around and gone home otherwise.

[chef1366]

Good call Brian (Keith). \\/