RE: Welcome to Club SAITO !
All:
Just made this post in another thread, it's something that is often forgotten. I think it's an important safety thing, so if it's old news to you please excuse me.
On a four stroke engine, because of the potentially violent backfire, you should never use a spinner with a plastic back plate, one pop and the prop can come flying off.
If you want to go cheap, there are several on the market with aluminum back plates and plastic cones, these should be your last choice other than the price. Using an electric starter you can have the cone shatter, if you hand start they will generally be OK.
The best is an all metal spinner.
Lowest priced ones are "Spin-Right," available from Cermark, your LHS, and others. The Spin-Right have some parts in some sizes cast, this makes them more prone to shattering in a crash where others might just bend, and allow straightening. Also, I have never gotten a Spin-Right that was not badly out of balance. This needs to be checked before mounting on the engine. Available in two and three blade cuts.
I have never used a Dave Brown spinner, but what I've seen seem to be of good quality. They have a fully machined back plate, the cone is formed by "Spinning" the metal. Since it is spun aluminum the metal has to be soft to allow the forming. The DB "Vortech" spinners are available in standard two and three blade cuts, or with special cuts for any propellor you want. Available direct and LHS.
The best of the lot are the "Tru-Turn" spinners. They are fully machined so they can use harder alloys than Dave Brown, and using the better alloys they are stronger as well. And they are light. I was very surprised to fine a Tru-Turn 2 1/2" three blade standard spinner was lighter than a Du-Bro plastic three blade spinner of the same size. You will pay for them though. pair of 2 1/2" 3b spinners with adapter nuts is close to $100 at your door. Standard cuts will cost less.
Bill.