I've been using and testing model airplane props on my motoyak for a couple of years now and have struck upon what I consider a significant improvement over the stock Minn Kota props. Results vary slightly with the type of kayak, the total load, and the conditions it is used (ie-wind direction) but I'm seeing a speed INCREASE of 1/2 to a full 1 MPH on high speed and a DECREASE in running amperage used as much as 4-6 amps! This means farther and faster on the same amount of battery power as compared to stock! Weedlessness is the same as stock props...both will foul in heavy vegetation. Its as durable as stock props, if fact, I hit a saltwater oyster reef at full tilt boogie and it sheared the pin and only nicked up the prop. The overall diameter is the same as the stock prop...10"
Now, these props do require a good bit of modification so I'm making a test batch of 6 to sell for $15 each delivered in Texas. I'm calling them HKS props (Hooked on Kayaks Speed Props). These will fit Minn Kota trolling motors with a 3 & 1/4" diameter housing (Endura 30, 40, 45 and many others). If your MK uses a MPK-2 or MPK-6 prop, then mine will fit your motor (see link chart)
http://www.trollingmotors.net/minn-kota-prop-selection
If you want to buy one of my HKS props , drop me a PM. I'll start production next week. Best Phishes ;-)