top end sputtering?

[honda rider118]

my shee is sputtering and has no power on top end... i messed with the air screws and replaced plugs and still nothing. but we did decide to put in the airbox vents and thats when the problem started was after that. we put the pipes on and rejetted like a month or 2 ago and yesterday decided to put the vents in. What could it be?

[dmfisher71]

man that could be a number of things. you say you rejetted the carb i would start there maybe you put in jets that are too big i know this will take a while but i would go down a size at a time just make sure you dont lean it out to much