I have a 2002 Yz 426f. So heres the story... A month ago i was riding and all of a sudden when i shifted insecond gear all it would do is lunge foreward and not pull. So i tore the motor and tranny apart, replaced the broken shift fork and put it all back together. It started up on 1st kick like normal, shifted through all gears and ran perfect. I rode it for about 30 minitues and out of the blue it does the EXACT same thing I havent tore the motor apart yet but im asuming that it has done it again. Once again its 2nd gear that it wont pull in. It pulls normally in all the other gears except 2nd. Why has it broke again? The gears, shifter drum, bearings all look like their in great condition even the local mechanic says so . Has this ever happend to any of you other guys? Please if you know anything reply to this i am in need of desprate help.