Ooops, I went to lunch and forgot to hit send. Here is what I came up with ...

I plan on getting a Moki 2.10. I get the impression that the Moki 1.8 and 2.10 have very very short crankshaft threads. Not much room for the prop nut, especially since some of the shaft is taken up by the thickness of the spinner back plate. I take it, this is what Willy RDRC is talking about. Unless the prop has a relatively thin hub, a special prop nut or spinner adapter will be required.

From doing a bit of reading I see that the Moki 2.10 has a 12mm diameter crankshaft (smooth) that is stepped down to 10mm threads. The Saito 120 is similar in that it has a 10mm shaft and 8mm threads.

In any event, the short crankshaft seems to be confirmed by jpmorgan's post since he is referring to a Tru-Turn "short shaft" spinner adapter (which is specifically designed to deal with this problem).

Attached is a pic of the Tru-Turn TT-0105-A adapter (from the Tru-Turn adapter selector). Just look at how deep the nut reaches into the prop hub. According to Tru-Turn, the nut has a 13.5mm (17/32") diameter (I called and asked).

So ... if I want to run a Tru-Turn spinner I am going to need to ream the prop to 12mm and form a 13.5mm (17/32”) counterbore to clear the Tru-Turn adapter. In order to do this, the proper tool is one of those Bennet prop drills. See this page:

http://www.bennettbuilt.com/page9.htm

It would probably make sense to order a 17/32” drill with a 12mm tip so you can ream and form the counterbore in one operation. Are we having fun yet ?

Well, here is some more. The Tru-Turn web site also mentions a special back plate. This no doubt provides a 12mm hole in the spinner backplate. Darn, the bigger you go, the more complicated things get.

So in order to run a Tru-Turn spinner (and I do love Tru-Turn spinners) I have to order a special spinner direct from Tru-Turn as well as ream and counterbore each and every single prop.

I wonder if I can use one of those cone shaped spinner nuts. The problem here is that 10mm is big, I don’t think Du-Bro makes one. I called PSP manufacturing since they sell these “Billet Spinners” (Prop Nuts) in various sizes (not 10mm thread though). See:

http://www.pspmfg.com/

The lady said they would make one in 10mm thread for like $9.00 (would take about a week). Perhaps this is the way to go.

Moses