Hey all.
think I got everything tuned up. Just one issue I'm not sure of. Engine make a fair amount of rattle noise. I have used a sethoscope. Normal running noise from head get the noise rattle/ grinding noise from the gear case output shaft area. Does it sound normal to you all?

thanks!!

 

"Grinding" would never be something I would consider normal on any engine.....

My stock 250 made a fair bit of piston slap noise when low in the rpm range, kacr jingled a lot at idle, and a normal valve ticking and can chain noise. Then again this is while my kacr was eating one of my valve tappets and I never had any idea...

Post a video clip

 

Just added a clip!

 

Adding another clips little louder rattle

 

Sounds like cam chain slap to me.

 

I am running a manual tensioner. Adjusted it few times and didn't make a difference.

 

Is there oil in it?

 

Definitely sounds cam chain to me also. Make sure you still have both plastic sliders in there correctly... Have seen a few motors where they were either not put back or were eaten away

 

1st vid sounds scarier.... I would have torn into it already if it was me. That light scratching/grinding sounds pretty bad... 2nd vid sounds like cam chain but not the 1st vid.

Also is it missing or was that ju st you in the throttle? Did not seem to be revving clean to me

 

Update. Tore whole engine apart. No bearing issues in gear case. Noticed that the washer
Behind the clutch pack has had some spinning wear not too sure why yet. Only thing I could find related to the noise was on the exhaust valve the timing chain was flexing off the cam gear as the cam was pushing the exhaust valves, would this be fixable by tightening up then tensioner or are we looking at new cam Chain and guides ?