2001 Yamaha Warrior YFM350x Clanking Noise

[Chase Cook]

I have a 2001 yamaha warrior YFM350x and started to work on it. The person who I got it from put a new top end kit in it. I already took the top end off and checked, brand new still. Had to clean the valves so it can get better compression. Put it back together and turned it over and and made good compression but also had a loud clanking noise at the bottom, put hand over carb and stopped making the noise when I turned it over. And won't start.  I know it is not the top end. Just cleaned it and valves. Need help trying to figure out what's the problem.. thinking it's the crank rod but don't know. If it is the rod can i just get a new rod for it?(would be great if so). Or does it need a hole bottom end . In need of help.

[MarkinAR]

Odd that restricting air flow would make any difference in the bottom of the motor. Not to be obtuse, but are you certain it's in the lower half? Normally the rods are pressed on the crank so not average DIY stuff. 

[Chase Cook]

Not sure. Just sound like it's at the bottom end.. I check the rod and moves side to side on the crank but don't know if that will effect it. Looks like the wrong size but not sure.. going to take the engine fully off the frame today and disassemble it..

[Frank Angerano]

When you have the head off again try to move the crank up and down to see if there is play in the bearing.  Not rotating but move up and down.  Any play in that direction and it a blown main bearing.  Side to side is ok.  

[JacobSlabach]

I would double check timing and valve adjustment first.  I hada bike that was clanking and found out I had checked the valve clearence at the wrong tdc.