Big Worm, ur dead right that when the chain stretches that IT WILL change the cam timing.
When the chain stretches, the links are just that little bit further apart. Now if you measure the distance of the timing teeth from the crank to the cam, u will find that it's (x)"/mm apart, when the chain stretches it will be that +a slightly extra because THE WHOLE chain has stretched.
So the fact is, the timing will be changed a few degrees but not a whole lot that it will badly effect the running of the engine.
My stepping stone to what I'm riding now.
Suzuki GSX250 '82
Suzuki GSX-R600 '00
Vulcan VN1600 Classic '06
Fitted: tachometer, genuine windshield, K Drive hard bags, upgraded Meanstreak clutch spring with Judges washers, Cobra Speedster Longshots, Dobeck TFI controller, Chucksters air filter plate, Mustang seats with drivers backrest.
Up coming items: volt meter, oil and temp gauges.