Do Not use sandpaper disks... they wear/sand out the prop drive hub and so on !!

Tight, Tight on the Prop and try richening up the mixture just a bit untill your engine is broken in some.
Seek an instructor if at all possible.

Then see below...

1. How ever with using APC Props I have found them so hard that nothing short of a couple of thin leather washers (one on each side of the prop) would allow them to stay put. Thin like in glove leather works best. Only use them once then discard and cut new ones if you must.

1a. Double nut as the 4 stroke folks do !

2. When using any spinner trim them to fit allowing no spinner edge to touch the prop except the rear spinner back plate itself. Plastic spinners can get old and brittle causing them to explode !! as can old composite props, if nicked or split dispose of them by sawing them in half with a hack saw at home. I have seen trash divers pull them out of the trash at the flying site..... !!

3. Do a (walk around ) safety inspection each time you prepare to fly not just when you get to the field ! Real Pilots Do This Everytime ! Set a routine and stick to it !


Fly Safe **

Cheers

GSNUT