I have a 1992 Basscat P2 with a Mercury XR6 150 on the standard 6" CMC manual jackplate. Got the boat 6 months ago, and this is my first bass boat. I had the engine fully serviced and mechanic said it was basically perfect and had very low hours. The boat is also in remarkable shape for it's age. It came with a 4 blade unbranded SS 23P prop. The issue is that at between 5000 to 5800 RPM it gets little to no acceleration. Top speed is 54-55 mph (GPS). And at 5600 to 5800 it feels like the prop loses and regains grip somehow. Speed stays about the same but RPM's jump, also the boat will pull to the right when it loses "grip" but then drives fine when it regains. When this happens to nose of the boat will instantly jump to the right, and can be a little scary sometimes. This has happened since I got the boat. As an inexperienced driver at first I thought it was because I had the trim too high, maybe venting or cavitation. Trimming down does not seem to help. And last weekend it did something new that makes me think that prop is possibly "spun". I punched the hotfoot from a pretty much dead stop, the bow rose as normal but before it planned out the RPM's suddenly spiked to 5800+ as if it slipped into neutral. I let off the gas and tried again and it took off fine. From my research this sounds sort of like a spun prop, but not exactly. Like I said, I'm new to this and any input you guys have would be greatly appreciated.