I have been running various BME engines ever since they were first produced and have yet to have a problem with the single bolt hub. I also ran a single bolt hub on my old 4.2 Precision Eagle glow engine and never had a problem with it either.

The BME hub is serrated and also tapped for 6-32 cap head screws. I insert the screws and then drill 2 holes in the spinner back plate just large enough to accept the screw heads. They keep the spinner back plate from rotating and since most spinner back plates are knurled and bite into the back of the prop, the prop doesn't move either when the nut is properly tightened. If you are using a wooden prop you should check the tightness of the bolt(s) regardless of how many there are as the wood can and will compress over time.

Len