If you really think the engine is OK but quad runs slow, then check the CVT. Worn out belt with too much deflection would decrease the top speed. It would be like trying to go fast in low gear. Install a tiny tach and check your max rpm which should be around 6500 rpm at WOT on stock motor/exhaust. If that checks out OK, the CVT belt needs to be either tightened or replaced. You are looking at minimum $120+ for belt replacement (in my area) if using an OEM belt (which seems to be the best quality in my experience). Call up some dealers and get a quote.

 

Check around & you can find a new Kawasaki OEM belt on-line for $60, if that is your problem.
Did you check the Muffler over as well?

 

I hope it is the belt im going to try it, it just kind of bogs it idles great and revs fine in nuetral i reset the belt , flipped the limp switch the only thing i didnt do was replace the belt i guess thats next I also replaced the exhaust with a Hmf full system.

 

did u re jet after new exhaust?

 

not yet but its running the same as it was before the exhaust Im going to rejet it as soon as its rideable

 

dude easy, i have one but if you burried it go to napa and buy a carb cleaning tank, $20. take carb(s) apart and take off all plastic and rubber parts and set aside. remove all brass parts, jets etc. put in tank for 20 minutes. you have gas passages the size of a human hair and that is the obvious problem. hose out thoroughly with water than blow out with air super thoroughly. back together and good to go. i fix all my friends quads and down on power is almost always carbs. the carb tank is no joke!!!

 

thank you to everyone for the help I took the carbs completely apart and cleaned them really good with brake parts cleaner, then replaced the plugs although they didnt look bad, this thing is BAD it pulls the front tires up easy and has plenty of power.

 

i have a full hmf exhaust on my 750 make sure u jet it or u will cook the back cylinder my friend did it . the back cylinder runs alot hotter

 

what size jets do I need?

 

Jets will depend on your altitude you ride at for sure, if it runs great and it does 60 or above isnt that enough?, buy a CDI from Dynatec and your launches will scare you and your top speed will increase 5-10 MPH. Mine did.