[asdf38]

I'm not getting the power I expect of the engine. Most of the time, I've to run at 3000rpm to make 5kts in slack tide. I've tried changing props several time (pitch & diameter) and in the end summise that I probably have some wore rings. I do return couple of years back, I made a 500nm passage (engine most of the way) and at the end of trip found the oil level to be alomost zero. I could only drain out 0.5-1 litre. I could have abused the engine on that trip. That's my suspect.

I think you're mistaken by blaming the engine.

All the engine does is spin the prop. If it's doing that but you're not getting good performance, it's not the engine's fault. Full throttle is usually 3400-3600. If you can get there, then you don't have power problems with the engine. Period.

Clean your prop and hull and cut down weight.