i need help with my 07 kx250f

[damian8605]

ok so i did a valve job on my bike i send it out everything sounds good in the engine but i have problems with back firing and wen it try to start it sometimes it starts on first kick but sometimes i need to kick it like 7 to 8 times rapidly and keep the throttle open and then it starts.. and wen its riding it spits until i bring it up to high rev.. i mess with the screw underneath the carb and nothing sems to help

?

[vaalloz]

What pilot jet are you using?

[damian8605]

i believe is the stock one.

[race250r]

Pull your head cover and check your timing, sounds like it is off.

Sometimes, the sprockets can actually rotate on the shaft. If this is the case, you will need to press it off, re-align it, press it back on, and spot weld the sprocket to the shaft.

Have fun and good luck.

[D-K]

Put in a #42 pilot jet and set the fuel screw at 2.5 turns out.

If you still have problems, check the timing, see if any cam sprocket moved on the shaft and check for air leaks both on the carb and exhaust.

[fivepointnine]

+1 on timing