The tensioner is on the top of the cylinder on the RH side.
The silver hex bolt just visible in the to the left and down a bit from the LH fuel pipe on the injector, just inside the radius of the pipe. It is difficult to get at with the engine fitted as it's under the seat tub. It is an auto adjuster so shouldn't need manual attention, but it is also not completely unknown for them to fail although you wouldn't say it's a common problem either.
22,000 is past the scheduled mileage for tappet adjustment, but mine has done 70,000 and it's never been done although for curiosity's sake I might have a look next spring before the annual bash.
To adjust clearances you remove the rear dampers and hoist the back of the motor as far up as possible then the rocker cover can be removed once the panels have all been removed. Fiddly knuckle scratcher probably but still a lot easier than removing the engine completely. You could probably replace the adjuster with the engine tipped like this. I think they come retracted and you bolt them on then remove that top bolt and with an allen key turn a lock screw inside which releases the plunger then put the bolt back and that's it.
