I'm in the middle of a top end rebuild right now and I want to make sure I get the cam chain in the right position.

In the manual it states having the rotor off so you can see the bottom cam chain sprocket. Mine is still in the bike and I don't have the tools to take it off.

Does the cam chain have a keeper or some sort of guide on it to keep the chain from skipping teeth on the bottom sprocket when you take the barrel and head off? Or am I going to have to build a rotor holder and a rotor puller just to make sure it's all still in tact?

All you need to do is set the piston at the correct TDC (your manual should tell you how)... After you set it to TDC install the camshaft so that the lobs are pointing down and install the cam sprocket and chain so that the timing marks on the sprocket line up with the mating surface on the head. The third mark on the sprocket should be up.

No need to take the rotor off. After you are done, turn the motor over by hand a few times after you get everything lined up to make sure there's no interference for when you go to start it.

Thanks! That saves me hours of needless angst. So I guess all that indication mark on the lower cam sprocket is for is to tell if the piston is at TDC then.

I bolted it all back up to together and spun the engine around a few times and all seems to be well.