Can someone tell me how to time my 400 Big Bear? It pops bad at mid range of all gears and i hear what appears to be the timing chain hitting the cover. I've got the chain cover off and the gear seem tight but the chain is loose.

 

Have you ever adjusted your valves?
You could have blockage in your carb.

You can check to see if your timing chain is streched by looking at your adjuster. The adjuster should be on the rr side of the cyll. Pull the center bolt outalong with the spring. Then remove the upper and lower bolts on the adjuster. Check to see how many clicks you have left before its all the way out.
I have never worked on a bigbear. All other quads that I wrked on had chain adjusters like this.

 

Maybe that's what i should have asked 1st. How do i align the motor to adjust the valves?

Bo

 

http://www.mudanddirt.com/tech.htm

You can download a kodiak 400 service manual here. Valve adjustment should basicly be the same. I know the valve clearance specs are the same as the BB.