Do the check and if you need the plug make it and install it. The install is all but two minutes. The measurement from the face of the tensioner casting to the top of the plunger
under 16 mm no plug needed 16 mm and deeper reqires the plug. Before you pull center nut put in 3rd gear and rock motor forwad to remove all slack in chain on the opposite crank side of tensioner.
Below is some pictures first remember tensioner is in the bike but first pisture is the face you measure from I was talking about.
second is the face on the top of the pluger I was reffering to. I collasped the pluger so you can see what surface I was talking about. The pen points to it.
plug is .393" X .375" you can get a grade 5 10 mm bolt cut the head off and file flat then cut a section 1/16" longer and file off flat and to 3/8".
When you pull the center plug do not try to turn motor over until center bolt is installed and torque to proper specs.
Easy job keep track of copper washer on center nut and re-use.
before you put the center nut in push on plunger to see if it goes in any.
install center nut and torque to specifications, start mot and have fun
130.00 my arse you can do this.