Hey, got a tech question for anyone out there. I have a 91 ex500 and when riding thru town, it's perfect. Once I get er up to about 70 or higher, it will suddenly decellerate back down to about 60 then lurch forward, adn rev up again. Even with the throttle open all the way, it will do this at higher speeds. Any hints, suggestions, or answers as to the problem? We have checked the plugs, fuel is fine, filter is fine, hoses aren't pinched......The only other thing I can think of is maybe the float bowl is not set properly, but even that was completely replaced right before November last year.

Any help would be greatly appreciated. I need to get out on the highway and get soem miles under my belt.
Thanks in advance.