I came up with a chain-adjustment method that minimizes slack, which should help maximize mileage, while avoiding over-tightening:
The factory recommends 3/4 to 1-1/2 inches of slack with the bike (NH750) on the side-stand, but how accurate is that? The ideal slack is as little as possible without ever getting tight, so I use my own procedure. I start by lubing it after a warm-up ride, then let it cool, maybe overnight, and on the center stand.
I remove the seat and route a tie-down strap over the bike frame, under the swing-arm on both sides, back over the bike frame, and hook the strap ends together. I then tighten the strap, compressing the rear springs, until the sprockets are in a straight line with the swing-arm pivot, which is where the chain will be tightest.
I then rotate the rear wheel several times while checking the chain for the least slack, as chains don't wear evenly. Once I find the position with the least slack, I adjust the chain for very little play, maybe 1/4 to 1/2 inch. That's as tight as it can be without the risk of it being too tight as the wheel moves.