So happy with my 4 blade..info to maybe help someone else.

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
I thought I would post my findings of my prop selection, maybe others can find it useful?

I have a 20-21 Cuddy/walk-around with a 140 looper Johnson with a 15.25x15". I tach'd out at 6000-6150. While I thought I was propped correctly, I found It took alot of RPM to keep me on-plane, and a decent cruise speed yielded 4500-5000 on the tach. dropping below 4200, I would fall back into the hole.

Lots of research later, determined I was doing a lot of spinning, and a 15x17 would make sense on my setup as I could afford a WOT RPM drop, with hopes to pickup ability to better stay on plane at lower rpm's, and better cruise.

THEN, I saw a craigslist ad in my town. A guy was selling a Turbo (Brand) "Ultima 4 4-Blade Stainless 14.75 x 15". In thinking about it..."IF" a 17p was my ideal in a 3 blade-knowing I'd loose WOT RPM by 200-300 possibly......Maybe, just maybe, this 4-blade in a 15p would not drop as much wot rpm, yet still give me the benefits of Lift, lower cruise RPM and better overall performance.

I bought it for $175.00 (it was almost brand-new) and my first water test, I could not believe the results. I only lost maybe 100 RPM from the Alum 3 blade 15x15.
I still see wot of 6000 (motor spec is 5500-6000), My overall speed is up 5mph. But the huge benefit is the ability to stay on plane with 3000-3200rpm, and a decent cruise is about 4k. Throttle response and hole shot is noticeably better. I have no negatives in either low, mid or High end.

No other changes were made at all. Just prop. Its like a different boat and motor actually.

Since I was so surprised with the results, I felt inclined to post, if someone has a similar setup and has some of the same issues I had. Could not be happier with this prop.
 

greasyhands

Recruit
Joined
Sep 3, 2017
Messages
2
I have a 1973 Capri Tri-hull with a 1983 Johnson 70hp. Got the motor running really well, but it had a terrible hole shot when I went tubing with the kids, granted its me, my wife, and 3 teenagers in the boat. Anyway it came with a 13 3/4 x17 3 blade. I ordered a Solas 4 blade 13 1/2 x 15 right here on Iboats, and it changed everything. It now gets right up on plane, my very slight bogging when going WOT is gone, and it stays on plane at a much lower RPM (have no tach, just going by sound). It has made a fun boat into a really really fun boat. I can't feel a difference in top end speed as I have no speedometer either, but we seldom go to the boards for long periods anyway. Anyway, going tubing again today, can't wait!
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
People seriously underestimate the differences different propellers can make. As a former Merc dealer, one of the first things I did when I bought my boat shop was to get ahold of all the different props I could sell as a dealer and give them a try... All the better to help advise customers. But yes, different props on different set ups can be the difference between fighting the boat and enjoying the boat.

With my own boat (and the original engine) just changing from a 17" 3 blade to a 15" 3 blade made a world of difference.

Thanks for posting your experiences.

Chris..........
 

stalker

Recruit
Joined
Jul 6, 2017
Messages
5
I was told a 4 blade prop would help getting my 18 Jon boat backing off the trailer in shallow water ? I have a 2005 50 hp mercury 2cycle any help please
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
I was told a 4 blade prop would help getting my 18 Jon boat backing off the trailer in shallow water ? I have a 2005 50 hp mercury 2cycle any help please

I'm sorry, I can't see how. Shallow water is always a challenge, and backing off into shallow water is dangerous (for the enigne and transom). Best just tilt the motor all the way up and push the boat off the trailer, if it only comes part way off, drive the car forward and pull the trailer out from under the boat...

Chris.........
 

82rude

Rear Admiral
Joined
May 8, 2012
Messages
4,082
Ive had a solas amita 4 blade for years now.Its was originally for a 1982 90 hp evinrude with the 13 spline large gearcase.Its now followed me to my ss160 starcraft and 2011 60 hp etec.I hit dead on 6000 rpm and a max of 34.9 mph gps.2900 rpm and low teens and still on plane.Ive tried a few other props that were ok but im always coming back to the amita.Thanks solas and thankyou iboats for having a good deal on it at the time.Best prop purchase ever for me.
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Yea, i was hesitant...it was a 175 gamble not fully knowing how it would go. An educated guess after the research her.

Incredible difference.
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
Great info and thanks for the post. Love to hear of different peoples experience with props. All helps towards the database.
4 blades sure have their place, but I prefer a well suited 3 blade for that bit of top end difference they offer over the 4 blade.
 
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