If you have a old wheel spoke laying around you can make a tool, just give it a few bends and mark the one part off in 1/8'' marks with a small grinder, I use it all the time, fits right inside the primary under the chain and makes adjustments easy, don't know if anyone sells them but easy enough to make.
I think that I paid $100. for it. I am very happy with the way it works. I find you really notice the benifit in a parking lot or slow traffic where you are on the clutch and throttle a lot.
kemo