Changed mine 5000km's ago, crank spun the grooves off the belt like a big grinder anyways there was no valve clearance issues with mine. Turn the engine to TDC #1 cyl, check to see that rotor is at # 1 position, line up the timing marks on the sprockets, install belt. This should be pretty close(should run, but not perfect) check with timing gun.
Mine is set at 10 degrees BTDC,
I got my book from crappy tire, it's not really detailed but it does give you all the tork specs etc..
Anyone know how you can go before ya lose top end?