Yes I'm new to an older 500 (98), i've ridden friends for awhile and broke down for an older starter machine. It arrived and ran very well (easily got it up to 60 going up an incline! :veryhappy. Well that was the first tank of gas, then i messed up by adding fuel with Seafoam in it (1 oz/gal). Within a mile the 500 noticed it and began bogging down with any attempt to go faster than about 12-15 mph. I replaced the fuel filter, no better. I also cleaned out the air filters (they were near clean to begin with). Did i manage to 'clean' out the tank and transfer the waste to the primary jet cloggin it so i need a carb rebuild now?