Prop questions.

[MTboatguy]

Ok, was doing a final inspection of the motor today on my new to me boat. It is a 16 foot Starcraft Super Sport I picked up a couple of weeks ago, it has a 1973 50 HP Lark on it, good running motor, but was noticing it has a small chunk out of one of the blades and a crack in another one. I am sure it is the stock 3 blade prop that came on the engine in 1973. So I figured probably time to pick up another prop, which of course there is a wide choice of props out there.

The wife and I do not ski, it is pretty much a boat for lazing around the lakes and doing some fishing, so really don't need anything radical on it, but figured I would ask, what I might look at to give a bit more bite and performance over the stock prop that came on it 45 years ago.

Thanks for any guidance you can offer.

 

[F_R]

OMC did a pretty darn good job of putting on a prop that would be suitable for the average boat the motor was likely to be used on. Furthermore, it was the dealer's responsibility to swap out the prop if it was not suitable (not that they all did). In other words, until proven otherwise, you probably are ok as is.

One thing I might suggest--It would seem you might be boating in skinny water and tearing up the prop. Consider a stainless steel one if so. MUCH stronger, it will pay for itself in the long run. Yep, they are expensive so it is advisable to be sure what is the best one before buying. Nice if you can try before paying.

 

[dingbat]

Computer design, new alloys and new forming techniques have improved prop design and performance significantly since 1973. Performance at a premium however...

Unless you have a particular problem your trying to solve, simply replacing the existing prop with the same size aluminum prop is your best beat....unless you need to reduce or increase rpm for some reason.

 

[jimmbo]

In 1973, props were rarely, if ever cupped. Modern props are almost always cupped. That difference may make a numerically identical replacement prop yield different rpm, speed, and hole shot than the original equipment.