Please help, Helix 150cc has no top end speed

[godfatherbr]

This is my first post. I have been reading the forum lately and have appreciated all of the knowledge being shared here. My small engine experience is very limited but I have learned a lot in here already.

I recently purchased a Helix 150. The kids are having fun with it but I know it can do a lot more. It starts perfect every time, it idles great, but when you get on the gas it just bogs down. If you put the pedal to the floor it hardly goes at all, if you back off to about 3/4 throttle it will pick up speed but slowly. The rpms can get nice and high in nuetral but once I put it in gear it just won't wind up. The guy I bought it from had just had it tuned up. The shop he took it to put in a new carb. I adjust the sir set screw to 2 1/2 turns out and messed around with it a bit from there but no change. I don't know what kind of jets are in it. The tune up also included a new spark plug. Any suggestions would be much appreciated. Thanks.

[2SlickNick]

Pull the carb and check the jets size, an check float height

[godfatherbr]

I can pull the carb and check the jet size (I think). But how do I check the float height and what should it be?

[bear]

also check your intake boot to make sure you aren't sucking air!

[2SlickNick]

Float height should be 18mm here is how i learned. ( thanks to 351stanger and this link)
http://www.allthingsmoto.com/forums/...mentary-13608/

[godfatherbr]

Thanks guys. I'll see what I can do.

[JERSEYDEVIL]

if it revs good in nuetral but bogs under load (in gear) you might want to check your belt/ clutches.

[godfatherbr]

I'm sorry, check them for what?