I have a 15 hp force motor and seen on here another had close to the same problem. But what my motor is doing is when I put it in gear and take off it will run ok tell about half throttle or so and then it revs and slows. The prop seems to quite turning. Slow it down and start over and the same thing happens. my question is where the prop is put together can that be seperating. I mean on the prop itself where the inter and outer part of the prop is put together. Or are we looking in farther to where the 90 degree is on the lower shaff.