Cam Chain Play

[Lynx]

My newly rebuilt 400 has just clocked up 500 miles on the road. So I decided to do an oil and filter change, re-torque the head bolts and adjust the valve clearances. One thing struck me which I found a bit strange was that I could roll the cam backwards and forwards a bit as there is some slack on the chain. Is this normal? I know on most bike the cam chain would be tight. I've tried slackening off the tensioner bolt with the engine off and running, but no change. It's a new chain and when I rebuilt it, all the tensioner parts looked good.

[tom400f]

The hole the tensioner rod runs in has a blanking cap at the top of it. It's common 400F procedure to remove this and press down gently on the rod with (say) a torx screwdriver while you loosen the pinch bolt. The spring on its own is not trusted to do the job.

Give that a try and see how it looks afterwards.

[Lynx]

Thanks Tom. That seems to have quietend the chain. So I presume the slack has gone.

[tom400f]

Ok great. With one of the tappet covers off (which is how I assumed you were observing the slack) you could rock the crank and see if there's any backlash in the valve movement...

[Lynx]

I had the cam box cover off to torque the head, but I'll try just a tappit cover.