Rattles from the front cover

[Hardware_Hank]

In some cases A upgrade kit if completely done can be spotted by lifting the fuel tank and looking at the ignition Harness to see if it has the updated plug.

Anyway by the book at 16 mm that gauge they send you would bottom out on the shoulder that is 16 mm, at that point they insert a spacer .390 inch by .355 inch, you can use a 3/8 inch or 10 mm bolt shank cut to .355 inch long. this increases the tension on the spring helping the adjuster work and hopefully not kick back.
So once you pull the center nut you will see a shoulder just down in on the plunger. In the view below for vision you are measuring the drop between the two arrows

if this drop exceeds the 16 mm the spacer goes in but they do not tell you what if anything after that. so the plunger only drops 25 mm well .520" to be exact. so if your plunger is way down of course add the spacer but be aware as the tension pressure is really decreasing especially if the plunger is bottoming out. This would indicate guides and at least chain. the gears on the cams most likely are good Still.

Are you versed with using a dial caliper? not to be a smart arse but not everyone is a machinist so I ask in case I need to provide you some measuring pictures?

I measured the tensioner drop at 23mm. Would you recommend doing a spacer, or just replace it with the chain and guides?

 

[warp9.9]

I measured the tensioner drop at 23mm. Would you recommend doing a spacer, or just replace it with the chain and guides?

so its almost fully extended you could add the spacer. but you still only have a couple teeth left on the auto-tensioner and it will not take up chain slack. this can be a problem if the chain gets loose and jumps a gear tooth. You do not have to replace the auto-tensioner at all it is just a mechanical piece. the problem is chain stretch and cam chain guide wear. once the worn and stretched parts are replaced the auto-tensioner plunger will be back to wear its supposed to be ready to adjust and keep chain slack from developing the only thing that could possibly prolong your changing of the worn parts is when you shim the valves you switch to Neville Lush's manual tensioner.