Replacing nicked up prop

[brooksville_rebel]

1987 Mercury OB 70 HP 2 stroke 3 cylinder. SN 0B228735. Not sure of the engines WOT or specs.
The prop is pretty beat up so thinking I should replace it. I can't find any number on it and the parts catalog didn't give me one. Not sure if its the original prop, looks like tho.
The Mercury prop selector on the Mercury site only goes to 2000. I picked 2000 and 75 Classic as the Engine just to see. Choose weight and good performance and it came back with a 14.06 pitch and 3 or 4 blades.

This is a 24ft Grumman pontoon used in the Gulf of Mexico in Hernando/Pasco County. Weight of boat/people/gear is rated to 2650lbs and we probably come close to that then add the engine so about 3000 - 3200 lbs I believe.
I am not interested in SS as I tend to bounce off the bottom in the flats and rather replace props and not lower units. .

Current prop from blade edge to blade edge is about 12 " 3 blade. No clue on its performance since we haven't put her in the water since mounting her on the boat.

Thanks
Semper Fi

 

[Scott Danforth]

Pontoons usually like bigger diameter, smaller pitch

 

[ahicks]

Prop part numbers (that can be Googled to get prop size), if they aren't on the side of the prop somewhere, are often difficult to see if you have the prop nut and locking washer in place. Once removed, they're generally easy to see - if they aren't all crudded up.

 

[Sea Rider]

Test current prop doesn't matter if slightly beaten at wot as usually loaded on calm water cond. Check achieved max wot revs, compare them to OB's min.max wot rpm range factory stated. Will know how much over propped that OB surely is, from there can go for a prop maximization to pull wot revs up with a less pitch prop.

If no clue which diam/pitch current prop is, take it to a prop shop and have it measured to know pitch number..

Happy Boating