Now leaning towards putting a 4-stroke in a Somethin' Extra (SE) ARF. If going the 4-stroke route, SIG recommends up to a .65.

So, I've looked at the O.S. FS-52 and FS-70 II Surpass as well as the Magnum XL-52RFS, and XL-61RFS. Are the O.S. 4-strokes worth the extra money compared to the new-generation Magnums? Is a Saito .65 too heavy/large for something like the SE. Are Saitos worth the expense?

Obviously, the gear height of the SE can be/is an issue with 4-strokes. Can you get by with a 3-bladed prop to bypass changing out the gear?

Some of the .50 - .70 range 4-strokes have a five to six oz. weight difference. When do you reach the point of diminishing returns when it comes to issues such as wing loading, etc.? On the SE, I imagine you want to keep it as light as possible, so would a .52 - .61 be more advantageous than the heavier .70s, etc.?

The fact that I'm actually at the decision point for a 4-stroke for my SE is a good thing!

Thanks for your input,

Ray
A.K.A. Mile-Hi Flyer