Originally Posted by korn
..Now, I read that you should be cruising around 80% of your max rated RPM, in this case 3600. So, my questions is; am I doing any damage by cruising at 1800 RPM? What specifically?
I'm not familiar with the specs of your motor, but suspect you mean that the max published rpm is 3600.
You can not check this at the dock in neutral. You should reach the max rpm with the throttle wide open and underway. Tachometers are notoriously inaccurate, but you should be within 100rpm or so. If you aren't, you are either over or under pitched.
Think of the pitch of your prop like the gears of a manual transmission in a car. If underpitched, its like running down the highway in 1st gear. If overpitched, its like going up hill in 5th gear. Both are bad for your motor.