I have an Aviastar .46 2-stroke engine for my Northstar kit seaplane. Problem is, it has an 8mm shaft. I can't find any 10" propellers with 8mm shaft holes, but that's the biggest prop an unmodified Northstar can take because of the clearance between nascelle and fuselage. I also can't find any adapters from 8mm to 6mm.

Any suggestions for propellers, and how to get them to fit?

Buy a prop reamer. Prop reamers are stepped, so they cut true cylindrical holes. ( common reamers are tapered) At your favorite hobby shop, or Tower.

I use a pillar drill to open up props to fit the shaft. With care it is not too difficult to make the holes concentric, and the pillar drill keeps the hole perpendicular.

Bennett Built sells pillar bits for props. Aka Kreg Bits or stepped bits.

http://www.bennettbuilt.com/shop/Pro...rill_8_mm.html

Charlie,
Great idea. Never knew they existed.
I wonder if there is a UK source

Thankyou for your help. I don't have a pillar drill, so I bought a prop reamer.