Break-in & prop selection

[Vronsky]

Hi All,
I'm getting fishing boat with a DF115ATL delivered in March next year. Dealer says he'll take care of the correct prop size. Determining correct prop size involves WOT I believe, and WOT is not recommended for new engines during break-in.

Unless I'm wrong here: how will the dealer be able to pick the right prop without going WOT ??

Or maybe the right prop is best determined after break-in ??

THANKS,
V.

[wilbur1]

If I remember right you can wot after the first 3hr. but for any longer than 5min. I have a 115atlss on a 20' aluminum bay boat. I had a 14x19 which was good till I raised the motor and ended up with a 14x21. Top speed is 39-40. Good Luck

[Harper]

Why not ask that question of your dealer? Seems you have adequate time to get an answer. You could be provided all sorts of opinions herein, but one on this forum can only guess what tools your dealer will employ to select the motor/prop/boat combination that he will sell to you.

He will likely employ experience, manufacturer's recommendations, perhaps some testing (without using any manuever that would require going past max break-in RPMs), but in the long-run, his decision is likely to be a best-guess.

So discussing your concern and understanding his reply and his approach to making such decisions will hopefully lead to a satisfying experience for you and a return customer for him. You can ask if, in case it doesn't turn out to be the correct prop, it can be swapped out. The prop selection depends not only on his knowledge of a given hull/motor combination, but also what YOUR normal load will be. Will you boat mostly with just you onboard, or will you have 6-8 people with you, as a rule. Will you be fishing, or primarily pulling skiers or tubers.

So many variables.....but you have the luxury of so much time. So use that time to sort it all out with your dealer.

[Murray]

i agree with Harper, it's in your dealers best interest to have a happy customer. Word of mouth is the best advertising your dealer can get.

[Vronsky]

THANKS.
Of course I'll bring this up with them in due time, but I always like to do some homework beforehand to understand subjects a little better.

[Moonlighter]

I agree with earlier comments.

The most likely scenario is that your dealer will have had experience with installing the same motor on the same or similar hulls many times. And thus knows what prop to choose.

There is no substitute for that experience.

My dealer has vast experience with Suzukis and picked the perfect prop for my boat straight up when I bought my boat some years ago.

Now take this further comment with a grain of salt, because I have no idea what boat you are having the motor installed on...... or what you are intending to use it for, or what your typical load will be.

My boat is 5.5 meters long, 18 deg V cuddy cabin hull made of heavy duty plate aluminium. Running a Suzuki DF115 2010 model, which is max recommended hp for the hull.

Prop is a Suzuki stainless 3 blade 14 x 20” pitch.

This particular prop is a very effective and popular choice on many similar boats for the 115/140 series motors, assuming of course that the engine hp is a good match for the hull. I get around 6100rpm at WOT with a typical load on board.

If your boat is something similar, then theres a good chance that this prop would be a strong candidate for your motor too.

Whatever prop you end up with, you want it to be able to reach around 6000rpm or even a touch more at WOT trimmed out. That will give you the best out of the hole and cruise performance.

[D'oh999]

My Dealer, (and this year) Water tested my boat before I even picked it up. I believed it would need around a 19", that is exactly where he started. Rev Limiter, so he tried a 21" and again Rev Limiter, wound up with a 23" and 6100 RPM 1/2 a tank.

He had to order a SS, and loaned me the Aluminum until it came. The Stainless still runs 6100 RPM, me and full of fuel. It gained 1 mph @ 48, but hole shot and midrange and cavitation on turns is night and day different.

The Dealer had it on the Rev Limiter twice, and WOT once within the first hour of it's life. Short periods won't hurt it. Running it at 3000 RPM for 3 hrs straight would do more damage. Vari the load every 3-5 minutes, don't run it above 4-4500 for longer than 3-5 minutes, you will be fine.

[Vronsky]

Great feedback, lads, much appreciated !

[dlnw98]

The Dealer had it on the Rev Limiter twice, and WOT once within the first hour of it's life. Short periods won't hurt it. Running it at 3000 RPM for 3 hrs straight would do more damage. Vari the load every 3-5 minutes, don't run it above 4-4500 for longer than 3-5 minutes, you will be fine.

Where, exactly, does Suzuki give that guidance for break-in and say "..you will be fine"?

Any reputable dealer, including mine, will give carte blanche to exchange props at no cost after the break-in period is complete. The ECM doesn't lie when Suzuki asks for a data download on a warranty claim...

[D'oh999]

Where, exactly, does Suzuki give that guidance for break-in and say "..you will be fine"?

Any reputable dealer, including mine, will give carte blanche to exchange props at no cost after the break-in period is complete. The ECM doesn't lie when Suzuki asks for a data download on a warranty claim...

Just tell them "You were Merging onto a busy Seaway".

What about the many boats that won't come on plane at 3000 RPM? Running 3 hrs at 3000 RPM on those, would actually require as much toque/throttle as running 4000/4500 RPM on a lighter boat,