9hundred$ride

01 kx125 bored .80 over. Will the stock carberator run this motor or will I need to jet the carb

outlawtr450

break it in first then put a new plug in it run it all the way through the gears and kill it wide open pull the spark plug and look at the color you want a milk choc color if its lighter than that move up one jet size

9hundred$ride

Hear is the problem. The bike will not start right now. Air,fuel, and spark are good. It has compression and like every third kick it back fires kinda. Its more like builds up pressure in the combustion chamber then it releases. I had this bike together 3 years ago and the only time it fired up it reved up real high so I hit the kill switch. Now after it sitting I want to get it going again. Any ideas

stev-o

sounds like your flooding out the motor and might need some carb work

outlawtr450

sounds like an air lear around the reeds or the carb boot

YZEATER

did you clean the carb?

zak873

did you happen to mess with the idle at all? I see people at the track all the time start up their bike and it idles SOOOOOO high, and once they shut the choke off, it calms down. I like mine to idle at a steady mid rpm until I turn the choke off.

YZEATER

can you bump start it?

9hundred$ride

Carb I cleaned before I put it back together

9hundred$ride

I had a difficult time figuring out the reed valves but I think I got it back together right. also I tried jump starting it a couple times and it didn't do anything. Once the bike revved up real high I hit the kill switch and I wouldn't start again

9hundred$ride

I have to pull the motor soon to paint the frame ill check the Reed valves again. Maybe ill just buy new ones. Ones in there are original to the bike.

jaymann

your reeds may be too tight, gotta remember gas has to get through there. you want like half screw past snug. as for idle check your main jet and needle or the idle screw, crank it all the way in and work it out till it sounds healthy.

zak873

you can't over tighten reeds.. I had an 85 punched out to a 100 and never changed jets, or anything, and it ran excellent with no problems.

9hundred$ride

I guess ill pull the Carb and strip it down again. Ill pull the cylinder and check those reeds again

zak873

you don't have to pull the cylinder to check the reeds..