HELP needed, t5 engine bogging

[jackskater]

right developed this problem a few weeks back and cant be bothered to mot my scooter because of it lol, basicly she pulls away fine and top end is amazing, in 2nd 3rd and 4th and gets into the top revs easyily, however mid range is horrendous it bogs right down and skips horribly to the extent i end up going up the slightest incline in 2nd or the really big hills 1st as it just wont power through it unless im on the flat, its a standard t5 kit, running a rh sterling and drilled air filter, its on a 118 jet which i know is big but the plug is chocolaty brown, if i get into into the powerband nothing stops it lol its just the horrendous midrange underload. any suggestions? my mixture screw is about 3 1/2 turns out aswell.
cheers in advance

[soulboy]

1/half turns on the air mixture mate

[jackskater]

surely if i have it one and a half turns out it will run lean in the lower rev range?

[paul d]

Have you a standard pipe you could try ? I've never tried a sterling exhaust but have tried a few others......in my experience standard T5's never work great with performance pipes . They just make an already narrow powerband even narrower ! Soulboy is on the mark with the airscrew but you could experiment . My scoot is about 13 turns out to compensate for a worn off rotary valve . warm up the bike and start adjusting the airscrew only turning a bit at a time . At some point you'll get the revs to rise , then fall slightly with the next adjustment . Turn the screw back to where the revs were highest and its job done .