The Magnum 61 will turn a 12-6 APC at 9700 whereas a Saito 56 will turn the same prop at 10,000 on 10% fuel. The Saito 72 turns a 13-6 prop at a little over 10,000. A Magnum 52 and the OS 52 turn a 11-6 prop at close to 10,000. A OS 46 caliber 2 stroke will turn a 11-6 at 12,000+. These would be ones like the Thunder Tiger Pro 46, GMS 46, Tower/Hobbico 46, and the Irvine 46.

If money is a problem and you need a lot of power, the Magnum XLS series 46 2 streoke might be in order. It's a new design that's just been out in the last 4 or 5 months. If you shop around, you might find one at a better price. They were on sale during the summer months. You have to make sure you are getting the XLS series and not the XL.

With a LT40 and a 46 2 stroke engine, loaded down with a camera, You need to run a large diameter - low pitch prop with the 46 2 stroke engines. I'm talking about a 12 X 4 prop.

When you run a 11" or greater diameter prop on a LT40 ground clearance begins to be a problem. You have to extend the nose gear all you can and put huge tires on it. Big tires are not a bad idea anyway if you not running on asphalt.

Good luck

Jim