04 KX125 NO POWERBAND

[hotrodkx125]

I Have A PROBLEM I JUST GOT A KX125 04 IT STARTS FIRST KICK BUT THE BIKE HAS VERY LITTLE POWER, LIKE THE POWERBAND IS GONE , WHEN IM IN 4TH GEAR THE BIKE ONLY GOES ABOUT 20-30 MPH HELP PLEASE WHAT CAN IT BE & HOW MUCH TO FIX

[Jeekinz]

check the powervalve is operating.

[DirtRider500R]

Clean out the muffler and replace the packing.

[kxpro8012345]

Sounds like the top end is gone i would get a new piston and rings check the power valve and do some maintence change the oil and clean the air filter But deffintly sounds like the top end is on its last leg barely running

[leafsrule16]

Piston and rings, check your powervalve, make sure the whole assembly is in working order and cleaned out and it should be good. If not, is there any major dents in your expansion chamber or other defects in your exhaust? Is it bolted on correctly? Is your carb gunked up? You could recheck your jetting and make sure it's not off too but chances are it's a top end being worn out or your powervalve.

[HolyKaw810]

Partially plugged silencer?

[ickfinger]

If powervalve is working, a compression test is your next step