I have a 1998 1200 custom that if you get over about 75 mph will cutout and die, when you slow up and shift down to 4th gear it will start up and run fine as long as you don't go to fast again. Had carb overhauled and still.does it. Thoughts? Thanks.

 

Gas tank vent hole clogged ??

 

Sounds like it is getting starved for fuel. Could be venting. It could be the petcock screen, or your vacuum is dropping enough to allow the petcock to close (if you still have a vacuum actuated petcock)? The more your throttle plate is open, the less vacuum being created.

 

Thanks for the replies. I meant to change gas cap, dealer was supposed to have changed peacock earlier this year when they did carb job. Will check.

 

Low float level will cause fuel starvation at 75 mph. Just drop the bowl and measure the float height.