I have an 84 ATC 200 that makes a strange LOUD clunking noise coming from the motor. It will not start. One day I went to start it and hit the electric starter and the starter was running but the motor was not turning over. then I pulled the pull starter out once. Then hit the electric starter and it was turning over but making the loud clunking noise. I currently have both side covers off the engine and everything looks fine. All the starter gears are good. Also the timing was good. It would not start with the electric or pull start. If you know anything it could be let me know, since I would hate to tear down this entire motor if I dont have to. Any help would be appreciated.
Thanks

 

ANYONE!!!!!!!

 

yep sounds like a broken rod i had that clanking noise in one of my old 200 atc's...this means pull that motor apart woot![img]i/expressions/face-icon-small-confused.gif[/img] not to bad though

 

But the motor does turn over. and has good compression and only a half of tank of gas on a fresh top end.

 

I rebuilt the top end in the spring and it ran perfectly, but I didn't put hardly no miles on it. I'm positive the timing is right. When the pistons on TDC both valves have the correct valve play. The spark plug is new. I was wondering if a stretched out timing chain could cause this. I did notice it seemed to have some play in it. Also the only little messup I had with the top end is I forgot to install the bolt that goes into the cam. The one that holds the CDI together. Once I put the bolt in though it ran perfectly though. It's hard to tell but I'm almost positive the noise is coming from the bottom end.