I’ve read a lot that ticking is normal. I’ve done the valves, though I’m going to do them again to make 100% sure I was on the compression stroke. Pretty sure okay was because there was play in the arms.

Is this what they sound like:

Here’s a video of mine.

Dan

’2000 Big Bear 400 2wd

 

Keep in mind that air cooled engines are built to looser tolerances due to expansion and contraction from heat extremes, where liquid cooled engines have tighter tolerances from being able to run at more consistant temp range. Most air cooled engines are noiser than liquid cooled engines for those reasons.

 

Aren't the 2000 big bear 400 models liquid cooled, as well? I might be mistaken, if so I apologize in advance.

 

Any update on this? My 06 kodiak 400 I just picked up sounds similar. Adjusted valves to spec and triple checked each time right where I left them. I also checked timing chain tensioner which still had plenty of room for adjustment and also checked slack (nice and snug). Not sure what else it could be.

 

THAT sounds like piston slap...

Had the same identical sound in a Bruin 350 I recently acquired, it was also smoking out of the tailpipe, burning oil. Valves were adjusted to spec perfectly fine, so I feared the problem was deeper. I pulled the top end apart to find this...

Replaced the piston, cylinder, and head (with a used one mind you), and it's quiet as can be now.

 

Sounds like both cam followers and piston slap to me. If you do take the cylinder off, strip out the rockers and check both them and cam lobes for wear too.

 

Great. It's not smoking so if it is piston slap I am really hoping it hasn't gouged the cylinder walls yet.. I did try and look at the cam lobes from the intake valve and they seemed fine no signs of wear but its hard to tell. I might pick up a mechanics stethoscope to see if I can narrow down where the noise is coming from.