Can anyone help bike starts and ticks over perfectly but when you open it up it holds back and trys to go but wont (40 mph top end)

it feels like fuel starvation to me as any one had this problem

Thanks

Beefy

Year of bike? condition? what have you done so far.

its an 1982 with 7000 miles on the clock all i have had done was the carb utrasonic cleaned the bike runs well until you give it some revs then it start to hold back trys to go but wont it does back fire when you let the revs off

thanks

is timing sorted?

Had the same problem on my mates 2KF xt600 , same carbs but it was getting a restricted fuel supply into the carb.

Check the fuel tap

Supply pipe

Worth also checking the elbow join going into the carb just to make sure theres no restriction there.

Other than than also check the small feed pipe linking the second stage carb.

TTB

Had similar issues with my '82 XT550....

Bought a new fuel tap.....cured the problem.

Hope your issues are as easily solved.

There may be a fuel filter screen in the carb float valve seat, there may also be a filter screen inside of the fuel tank...check these are clean

Hey Yamahead It's nice to see you back on the forum

There may be a fuel filter screen in the carb float valve seat, there may also be a filter screen inside of the fuel tank...check these are clean

Hey Yamahead It's nice to see you back on the forum

The one in the float valve seat was the one we found that was clogged on my mates, at first i thought it was a fag butt.

TTB

many thanks will try this weekend