Prop?

[Texas Prowler]

What size prop did a 73 Johnson 50hp come with? Mines a little beat and I'm not sure if it's even original to the outboard. I know there's prop calculators out there, but I'm looking for real life experienced responses. The boat is a 59 Smith craft. 13' 9" total weight estimated approx 800lbs. Thanks in advance. Boats max hp is 50 transom has been replaced. I have not had the boat on the water yet. The prop the shop gave me is chewed up a bit. He gave me a stainless one but it's heavy, so I'd rather stay with an aluminum prop. Thanks in advance. The prop i currently have has the numbers 13-3/4x 15 or 16

 

[jimmbo]

The prop that shipped with the engine was a 13 1/4 X 15. That however may not be the correct prop for your use. Also back then, the props didn't have very much if any cup in the blades, so a new prop with a 15 inch pitch might perform quite differently.
Your boat is on the small side for that engine, so I would say a 15 or a 17 would probably be close. Your engine WOT rpm range is 5000 - 6000. The goal is to try and get a prop that allows the engine to rev as close the to 6000 area, with exceeding it

 

[Texas Prowler]

Thanks man. The boat itself weighs 400lbs. And is a run about