I just read a service manual page, which states:
Crankshaft end play: .0025"-.0085"
Crankshaft end play max wear limit: .012"
Make of that what you will.
My thoughts are that crankshaft end play is not going to be what kills your motor. It'll be worn rod bearings or something like that.
Usually, though, "end of life" ends up just being the point at which your motor starts drinking a quart of oil every 50 miles or worse, due to the rings being completely trash.
Honestly, you've got two choices:
1. Keep an ear out for strange noises, watch for metal shavings in the oil and just run her.
2. Rebuild the motor, at least putting new rings and bearings in it.
Now, I hate to say this as an IDI lover... but don't count on a single vehicle. Period. Things break, new or old. Make sure you have a backup option available to you, and plan for failure.
"planning for failure" means making sure you put some savings aside in case something major *does* go wrong.
It means making sure you have a phone and triple-A when you go on a long trip, or having friends along the way.
It means keeping tools with you, knowing what to do if things aren't right.
Now, I personally have been lucky when it comes to not having a catastrophic failure, or getting stuck 500 miles from home. But a lot of that is taking care of your machine, and if things change, something isn't right... that's when you check it out.
