Hello, i picked up a 2009 gs500f a couple weeks ago that was non-running. Cleaned the carbs and all that good stuff, now the bike runs fine....Until i get on the highway. For whatever reason i can not seem to get the bike to go over 60 mph. The carbs have been cleaned, changed oil, and put in a new air filter. It starts up with no problems and when rode in town it rides just fine. As soon as i get on the open road the bike refuses to go over 60 unless going downhill and that works until it levels out then it just drops back down to 60. Any and all advice will be appreciated.

Does the bike feel like its running out of fuel, like lurching/surging as you try to accelerate?
Did you check the float height?
Have you checked for vacuum leaks or pulled the spark plugs?
Is your tank rust-free?

Does the bike act normally under 60 mph if you give it full throttle? Like full throttle in 1st gear?

Is it related to throttle position. Like it gives up @ say 1/2 throttle regardless of gear. In 2nd that may be 7000, 3rd would be 6000, 4th 5000 etc -
If so you have a tiny rip in a diaphragm, or you didn't seat one properly.

Cool.
Buddha.

Quote from: Bluesmudge on May 20, 2020, 04:39:36 PM
Does the bike feel like its running out of fuel, like lurching/surging as you try to accelerate?
Did you check the float height?
Have you checked for vacuum leaks or pulled the spark plugs?
Is your tank rust-free?

Does the bike act normally under 60 mph if you give it full throttle? Like full throttle in 1st gear?

I did change the spark plugs and the floats were adjusted while cleaning the carbs. The bike does act normal in low gears. I can get to 60 in 3rd gear but even when sifting into 4th it still wont go above 60.

Quote from: The Buddha on May 20, 2020, 04:53:06 PM
Is it related to throttle position. Like it gives up @ say 1/2 throttle regardless of gear. In 2nd that may be 7000, 3rd would be 6000, 4th 5000 etc -
If so you have a tiny rip in a diaphragm, or you didn't seat one properly.

Cool.
Buddha.

That may be an issue i will have to test out in the morning. Thanks!