Join Date: Apr 2012
Location: Greater Vancouver
Hey Mad, there are quite a few threads on here about how to align & tension the belt. You can use the hash marks on the adjusters and bike frame to get things fairly close as well.
Your "measurement" method may be a decent start. If you have a jack so you can pick up the rear wheel, you can gently run the bike idling in first gear, and watch how the belt tracks on the rear pulley. If you are running the stock pulley, you will want the belt to run more to the outside of the pulley. Make sure you test your belt tension before you start. Obviously without the bike running!
Some folks test belt tension by selecting a location where you can get a decent grip on the belt, and attempt to roll it (twist it) about 30-45 degrees with decent pressure. Don't try and break your fingers, just try to twist the belt. If you can twist it 90 degrees it is too loose. If you cannot twist the belt at all, or only maybe 10 or 20 degrees, it is too tight.
Once you are happy, go ride it. If the belt is mis-aligned, it will make lots of squeaking / chirping / rubbing noises.
Do a search on here to find many more technical descriptions of belt alignment and tightening. The service manual will also discuss this.
Use all information at your own risk. E&OE.