Re: Another prop question
You have more to worry about than top end speed. By reducing pitch to lower trolling speed means you run the risk of over-reving the engine. That can happen very easily with a low pitch prop. We cannot see your engine so we have no idea what prop you have. The engine was likely not shipped with one when new because the manufacturer does not know what type of boat (or barge, or pontoon) the engine would be installed on. all of them take a different prop. Diameter and pitch are typically stamped or cast on the hub between the blades or on the hub face behind the prop nut. You are looking for numbers like 13-3/4 x 19 (13-3/4 being diameter). 19 is the pitch. What ever that number is on the prop you have now, you would likely need to drop pitch at east 15 to be of any benefit. That equates to about 800 rpm (or more due to the light loading) at the high end thus the over reving situation.
