gpschult

What's the correct way to install an aluminum prop nut spinner onto a glow engine's drive shaft? I screwed one on to an O.S. 46LA and tightened it down by putting a drill bit through the hole in the front, using that for extra torque. The nut felt very snug when I finished, and the engine turned fine when I rotated the prop. But when I put an electric starter to it, the nut twisted right off and spun like a top on the ground. I'm guess I'm not too surprised that happened, because I suspect I'm missing a step somewhere. Any advice?

I am using a washer between the nut and the prop, but I can't imagine that has anything to do with it. The prop hub is pressed against the drive hub.

GREG DOE

Good question if you haven't been there before. First a good drill bit is too hard for this job, because it will snap and break before you get the spinner nut tight. My quickest go to tool is a allen wrench suitable for 6/32' screws. My second go to tool is a 1/8" piece of "music wire" like landing gear wire. Your rod, or allen wrench should be at least 6" long, more is better. When you have the spinner nut snug, grasp the propeller, and tighten as tight as you can. In the past I have broken wooden propellers, (and that might have been a good thing!) but I've never broken a fiber filled nylon prop (APC, or Master Air Screw). If your starter continues to loosen the spinner nut, just tighten it a little more. Good luck, and let us know how things work out.

706jim

I use a 7/8" box wrench.

THAT will tighten the nut.

1200SportsterRider

Make sure there is no fuel in the engine or it will kick back and spin the nut off.

gpschult

Thanks for your help! Sounds like I'm just not tightening enough, and the drill bit is too short. I'll try it with a longer allen wrench, will let you know if I have other problems.

gpschult

Thanks! Another dumb question... do you clamp it around the nut? Does it slip at all on the nut, given the nut's rounded shape?

GREG DOE

706jim said he used a 7/8" box wrench on a round spinner nut? I guess he must file, or grind a hex pattern on them? The old Harry Higley safety prop nuts had a hex pattern, as well as a hole for a rod to tighten the nut. I've not seen any of the DuBro prop nuts with a hex, but that could be a more recent design?

A. J. Clark

I like to use a line up tool to crank it down.

gpschult

Could be. Mine is rounded, so I was curious about that as well.

706jim

It's been several years since I bought these prop nuts. At the time, all of mine were made from 7/8" hex bar stock, so the 7/8 wrench was the logical way to tighten them. If they are now completely round your best bet would be channel lock pliers with rag wrapped around the nut to prevent marring them.

gpschult

Thanks! It would be nice to have a nut like that, might make things easier!

GREG DOE

Once again there is a reason why there is a hole through the prop nut, so that you don't have to use "channel lock pliers on them". He was probably just joking?

706jim

If some sort of rod through the hole in the spinner doesn't work, channel locks with a rag be my next course of action.

jaka54

Hi!
I make my own alu spinner nuts! I have used drill bits or any other round 3.6mm steel rod to secure them without any getting loose when using a electric starter.
See to that the engine isn't filled with fuel when you try to start. Flipp it first a couple of times!

1200SportsterRider

Thanks Jan, for backing me up on that, (no fuel in the engine), no need for prime when using a starter.

Nice prop nuts, I haven't tried that on on my lathe yet.