Summerwind...
All good info, but you are referring to checking the engine drive washer and shaft. I think we are mostly discussing the prop. If you have a prop that has a rear hub surface that is not perfectly parallel to the prop blades then that prop is not going to track correctly. The only way one can check a prop for tracking is to use a prop. I understand the fact that if the crank or drive washer is out of wack this would cause a tracking problem,but most guys don't have the proper equipment to check the precise measurements of an engines components.

Mustangman,
I wouldn't lose any sleep over tracking. Like I said in my previous post. I believe it makes a difference, BUT not as critical as a balanced prop. I always check for tracking only because I want the system to run as smooth as possible. Do allot of guys check tracking? NO, most guys I talk to have never done it.

Now that you are aware of it check some of your props just to see how far off they are. You may be surprised.

By the way, I bought my tapered reamer at at my LHS. The owner who has been in this hobby for many years suggested it. It's the only thing he uses.