It was a simple job to press out the old bearing (which I made a bit of a mess of in my haste) and press in a new one with a larger ID. The new one is a 12x16x14mm drawn cup needle roller.
It was simple (for me anyway) to do my usual modifications to the center pin (drill and tap for M7), make a clearance hole in the slotted end for my M7 bolt and just put the parts together.
It went together far too easily......
I really like this Kawasaki part because of the intelligent use of rubber cushioning with the wear resistance of a steel part.
It should be quite quiet in operation. It just makes me smile that this could be achieved with a minimum of effort...... :-)
I just ordered some M12 shim washers to take up the side clearance between wheel and tensioner arm and that should be all finished.
G