Mercury prop size question.

[JT36]

I have a 1995 Mercury 40 HP serial # 0G209821, model 1040412RD and need to know what size prop would have came standard on it in 1995?

 

[steelespike]

While the motor may have had a supplied prop the final size would depend on what the motor is on and typical activities.
I do believe the typical size would be "about" 11 or 12" pitch.But the actual size would depend on the application
If you don't have a prop tell us about your boat details,brand, year, size,dry weight, material,typical load.and activity.
The whole purpose of prop selection is to get the motor to operate within its wot(wide open throttle) rated rpm range.
If you have a prop the size should be near the base of the blades or under the prop nut.

 

[JT36]

Thanks for your response. The Boat is a 1995 StarCraft aluminum hull Starcaster 1700 bass boat,17' long and the load weight is 1,050 lbs. Not sure of dry weight. I use it mainly for fishing but do take the wife out for a leisure day on the water one in a while. When I have 3 people in the boat it definitely runs better when 1 person is clear up front. Still can only get 4,800 RPM out of it though. Recommended WOT is 5,000-5,500 RPM. Stamped on the prop is 48-73138 A40L 14P.

 

[steelespike]

Would be better if we had the gps speed to go with your lightly loaded numbers.Your pitch is 14" and probably too much for that boat.
The boat is decidedly under powered. Your lightly loaded wot numbers will tell us better what size prop is needed.

 

[JT36]

I think I'm going to try a 12" and see if that helps get it up to the 5,500 RPM #. Will take it out next week and let you know. Tag on boat says I could take the motor size up to 90HP. Don't want to spend the $$$$ right now on a new one. Especially since this one still runs well. Again, I'll let you know how it goes.