Need Help Quick!

[Woodsracer400ex]

2004 400ex Stock motor, one season on motor I race XC. I have a race this weekend and I noticed the motor is making a claking sound in 2nd gear when I ride at slow speeds. I doesn't make the sound in any other gear and when you open it up in 2nd it runs fine but when you let off the gas it makes the clak sound. I can't figure out why its making this sound. I tighten the chain, change and changed the oil, nothing is grinding or binding up. It sounds like something in the motor, I drives fine, my question is can I race this weekend without destroying the motor and what could it be?:ermm:

[ride_red666]

did you find metal shavings in your oil?

[Woodsracer400ex]

did not find shavings in oil.

[Woodsracer400ex]

just rode it this morning, shifts and acclerates fine. Just the claking noise in second in the first part of gasing it and then when youlet off. My race is tomorrow morning, I'm just going to say the heck with it and race. Would it be cheaper to buy a used 400ex motor than split the cases and replace second gear?

[4everhonda]

I've had that same problem for well over a year now, I dont have any idea what it is but I still rides fine. I would also like to know what I need to replace to fix it. You should be fine on your race tho.

[Woodsracer400ex]

I'm pretty sure 2nd gear lost a tooth or one of the dogs is messing up. I'm going to race tomorrow and then split the cases. I have had the worst luck with 400ex the motor is completely stock and I baby it, well not when I'm racing but first it was a blown head gasket from a stud pulling and now a gear problem? Better off buying another motor.