timmersuds

I have a question about installing the prop and flex shaft in a Blackjack 55.

Should the prop be flush against the propellor strut before locking down the set screw to lock it in place or should there be a small gap between the prop and the strut?

I checked my local hobby shop and I saw factory models installed both ways.

Thanks

amax

You should have a 1\8" to 3\16"in gap between the Drive Dog(The piece with the set screw that locks into the front of the prop) and the Strut. When Torque is applied to the Flex Shaft it winds up and gets a Little Shorter. Think of it like ringing the water out of a towel, or one of the old Rubber Band Airplanes.

PEERPSI

Umm, not quite. Black Jack uses a square drive that pushes on the strut not the engine. The drive end floats free in the clutch bell. The prop will work it's way to the strut either way. When you push it there during setup the thing to check is that the prop shaft is not pushing on the stuffing tube otherwise you will wear the stuffing tube. Much easier to replace thrust washers then a stuffing tube.