I’ve been a proud owner of a MX 2025 for a second season now and I’ve had the chance to do some prop testing that I thought I would share with everyone. I should point out that this info would potentially be useful to other boaters in general principal but it should be noted that my testing has been done on a MX 2025 with a 300 Yamaha Off-Shore outboard.
As anyone that’s messed around with props will tell you, any choice you make is going to be a compromise. A “speed” prop, one that gives you the best top end speed at wide open throttle (WOT) when running light loads, is unlikely to be a top choice if you’re running with heavy loads in big water.
I’m not one to be all that concerned with top speed. I want control in big waves and the ability to move heavy loads as I often carry 3 people plus myself and a lot of gear. While top speed numbers seem to get all the press, when you’re on big water you’re rarely if ever presented with the opportunity to drop the hammer for a WOT run. In that scenario I find myself spending most of my time running at 13 – 25 mph. 2 – 4 foot waves just don’t allow for much more speed unless you’re willing to beat yourself, passengers and gear unnecessarily.
I started my testing running a 20 pitch Turbo 1. http://www.turbo-props.com/products/turbo-1-series_t1s
This prop gave me the best top speed numbers of any prop tested and the hole shot was very, very good. As soon as you hit the throttle the boat lunges forward with very minimal bow rise. Mid-range acceleration is good, but not great. At 6000 RPM this prop will regularly produce top speeds of 60 – 61.8 MPH under ideal conditions (light chop, light load). When running on plane with this prop the boat sits very flat to the water with little bow lift. If all I fished was smaller bodies of water where 2+ foot waves were unlikely and my loads would be kept light (2-3 anglers + gear) this would be the prop to have.
It is on big water where the 20 Turbo 1 just didn’t seem to be doing the job I needed it to do. As I noted, mid-range acceleration with the Turbo 1 was fairly mediocre. Of course I didn’t realize how mediocre it was until I started trying other props! The Turbo 1 also provided very little bow lift which is incredibly important in big water. When running the Turbo 1 I had a hard time lifting my bow and keeping it up between waves. Also, acceleration up and over waves seemed to be slower than it should have been given I have 300 HP ready and waiting at the touch of the throttle. Overall in big water I’d give the 20 Turbo 1 pretty low marks.
So I started playing around with props. Skeeter Boat Center is close to me and has a nice prop loaner program that makes this kind of testing possible.
My first round of testing looking for an ideal “big water” prop started with the 21 pitch Saltwater Series II Yamaha prop. http://www.yamaha-motor.com/outboard/powermatched/2010_prop_pdfs/Yamaha_Propeller_Descriptions.pdf
Here’s the description of the Saltwater II from the manufacturer’s literature –
“Aggressive rake and extra cupping on the blades provides superior mid-range fuel efficiency, along with excellent anti-ventilation characteristics. For offshore fishermen, that translates to longer cruising range and better handling in rough seas.”
The first thing I noticed when running the 21 Saltwater II was a slower hole shot due to the increase in cupping and the increase in pitch from 20 to 21. When running an average load (2 anglers + gear and fuel) it was more than adequate but definitely not as fast as the Turbo 1. Where I immediately noticed a difference was in the mid-range throttle response! Once on plane the 21 Saltwater II is a rocket ship. When you touch the throttle you GO! Where the Turbo 1 felt like it was slipping at mid-range resulting in mediocre throttle response the 21 Saltwater II felt like I was being shot out of a cannon any time I requested more power from the 300 Off-Shore! Bow lift and control was noticeably improved as I was able to hold the bow high coming off waves versus losing control of it after each big wave when running the Turbo 1. My MX 2025 also seemed to ride higher in the water at the transom due to the addition lift being created by the switch to the 21 Saltwater II. Top speed numbers were very comparable to the Turbo 1 with the 21 Saltwater II hitting the 59 – 60 MPH mark any time I had opportunity to take it for a WOT run.
My next move was to test the 19 pitch Saltwater II. I was headed to Lake Superior this last weekend to do some laker fishing with a couple friends and we were expecting to have to deal with some big water. As I’m never, ever, able to make high speed runs on this body of water due to the wave height, I wasn’t concerned with potential loss of top end speed with this prop. More often than not I’m running sub-25 MPH on this body of water so what I wanted was a prop that would provide as much bow lift and mid-range throttle response as possible.
The 19 Saltwater II did not disappoint. In fact, I found some other benefits I didn’t expect, in addition to the bow lift and mid-range throttle response I was seeking.
The 19 Saltwater II provided a very strong hole shot as most would expect. I was carrying 3 big guys, a 100# cooler, 24 gallons of gas in cans + a full tank of fuel in the belly of the MX 2025, my trout and salmon box which weighs approximately 80#… and full camping gear for 3. If you can envision a cross between a fishing boat and Sanford and Sons’ junk yard truck… you’ve got the idea. We were loaded to the gunnels! So when I hit the throttle I was expecting a slug out of the hole. What I got was a hole shot on par with the 21 Saltwater II at light load! I also experienced incredible control in 2 – 4 foot waves that I just wasn’t seeing with the 20 turbo 1 or the 21 Saltwater II. Bow lift was incredible due to the increased RPMs at a given speed and the aggressive cupping made for a rock solid feel to my ability to control the bow in between waves.
The lift at the transom felt similar to what I was experiencing with the 21 Saltwater II. Some other things I noticed were my minimum planing speed dropped from 13 – 15 mph to 11 – 12 mph. That might not seem like much but when the transom of your boat starts to “sink” between each wave instead of staying on plane that forces the driver to hammer down on the throttle. This move can produce the desired effect of getting back fully on plane, or, what happens often is the burst of speed results in a couple rough impacts with waves before the driver is able to settle back into full control. That scenario just didn’t happen with the 19 Saltwater II.
My running speed in rough conditions increased significantly with the 19 Saltwater II over other props due to the incredible bow control and this improved handling characteristic only became more pronounced once we offloaded all our extra weight and limited ourselves to normal fishing gear. Instead of running 14 – 19 mph in big waves I found I was able to pick up the pace a bit and run 18 – 25 mph in complete control and comfort.
I also saw a huge improvement in fuel consumption with the 19 Saltwater II. I normally see 2.2 – 2.5 mpg when running in big water carrying similar loads with the 20 Turbo 1. With the 19 Saltwater II I was seeing 2.8 – 3.5 mpg and I rarely had to put the hammer down to counter a big wave which makes for a very smooth ride for the driver and passengers.
I only had one opportunity to test the 19 Saltwater II at anything approaching WOT due to the conditions on the lake. I was able to make one high speed run in a secluded bay where waves were running 0.5 foot or so. I was expecting a significant reduction in top end speed before hitting the rev-limiter. With a significantly smaller pitch prop that is one of the trade-offs, of course. Oddly, I was able to hit 55 MPH in my single WOT run with a few RPMs left to spare so even despite all the improvements in big water handling and improvements in fuel economy the 19 Saltwater II was no slouch when it came time to make a fast move.
My next step will be to test a 20 Saltwater II to see if I can find a sweet spot between big water handling and top end speed. If I can’t lay hands on one to test I’ll definitely be buying that 19 Saltwater II for big water use. The ride on the MX 2025 is very good in big water, even with the 20 Turbo 1, but when you add a prop with more aggressive cupping… the ride and handling gets much better. If you’re a MX 2025 owner and you frequent big water and / or carry heavy loads, you’ll want to consider doing some prop testing of your own. What can be gained, improved ride, big water handling and fuel economy, more than off-sets the loss of a few MPH at top speed and makes a very good boat even better!
I’ll report back if I can get my hands on 20 Saltwater II.
