Took the bike out for about an hour in our warmer weather today in Colorado. The bike ran great until I turned for home and got on the highway. At around 60 mph I was giving it gas and the engine started bogging down intermittently. Was able to get home, but I'm not sure how to go about diagnosing the issue. Seemed to run and accelerate fine the last 5 miles or so (lower revs through the city). Just wondering what the likeliest issues are - like a top 5 to start checking. I've looked at other threads and the list seems long for potential problems. For background - I've replaced fuel filter (but did not change internal fuel line - wasn't thinking at the time), haven't messed with throttle bodies, air filter looks good. I haven't ridden the bike much in the last year or so but am getting time to get back on it. Between my Clymer manual and YouTube I can do most of the work, but I just don't have the real knowledge for going about a diagnosis. Thanks for any input.