2005 Polaris rmk 800 not opening up

[Jabs64]

So my 2005 Polaris rmk 800 151 is not opening up it has great hole shot but after that it’s doggy! Just put a Indy specialties bottom end in and bored it out .050 with wiseco pistons I have 160 psi in each cylinder carbs are spotless I have 490 jets in and has slp twins any help greatly appreciated..

 

[Thutchison]

Had this on a phayzer, look at your clutching, I have no idea why . . . But the primary not opening up Caused that one to bog hard, especially after about 40.

 

[willjogervais]

check your exhaust valves, if they aren't opening up you won't have anything over 7kish

 

[Dazzler]

As per Willjogervais post, it sounds like a ruptured diaphragm on your exhaust valve. With engine idling, look at the exhaust valve cap for puff of smoke/exhaust coming out of the breather hole..