I just got my new BME 110 and it has two small socket head machine bolts tapped into the drive washer. Their instructions are a bit patchy. Do I drill small holes completely through the new prop hub , the spinner backplate and into the tapped holes in the thrust washer to keep the prop from slipping?

Nope, actually, you drill holes in the backplate of your spinner for the socket head bolts. If your backplate is the same as mine, it is thicker than the heads, so you can just drill it, and the prop doesn't need anything else. If your backplate is thinner, you'll have to drill some holes in the back of the prop deep enough that the heads can fit inside. A Tru-Turn spinner has really nice knurling and a fairly thick backplate, so that's what I ended up using. I have never had the prop move with this system, but you do want to make sure it's TIGHT!

HTH
Jim

You need to use those two screws to attach your spinner. With teh spinner attached and the bolts installed, I attached my prop in the position I want then tighten down the propeller enough to make an impression on the back. I then blind drill the holes to give clearance for the heads then install the propeller. WOrks great!

So you are saying that he prop itself need not be drilled?

Correct skip. The two bolts are there to prevent the spinner backplate from rotating.
If, however the heads of the bolts stick out past the backplate (which they shouldn't) you may have to drill into the prop. Make sure the 2 bolts are tight before installing the spinner backplate.

Thanks, I see the light now!!

Yes, the propeller will have to be drilled.
Just a blind hole to allow the head of the screws to go in.
When my wife gets home, I can take a picture if you need me too.

Must depend on the spinner. I have used both a ZN CF and a dave brown and neither one required the prop to be drilled.