Props for twin Evinrude 115 v4

[seven_magnum]

Last year was a success with the boat but I have a couple little things to work on. The boat and motors are 1988 pursuit 2200 with twin evinrude 115 v4. One thing I'm looking to change is the props. It's currently wearing aluminum 3 blade 12 and 3/4 by 21. Wide open throttle I'm about 5400 RPMs and 35 miles an hour. The biggest problem I'm having is a 25 mile an hour speed limit for a lot of the year. It is a struggle to keep it on plane at speed. I am moving a lot of weight forward, but I think 4 blade props would also be a big help. I really dont need speed, just the ability to plane at slow speeds and as much efficiency as possible.

I am not opposed to going with stainless props, they dont seem as expensive as I had thought. Any reason to shy away from a stainless 4 blade? And if I go that route, should I drop to say a 19 pitch?

Boat is in fresh water lakes 99% of the time with maybe one or two trips to salt water.

Thanks!

 

[WesNewell]

If your goal is to get on plane and stay there at lower speeds, you should look at trim tabs. While a 4 blade prop may help you get on plane faster, you will still need the speed to stay on plane

 

[Texasmark]

4 blades and shallower pitch, allows you to run a higher rpm at your selected speed which gives you more control on your attitude.....meaning that if you are running at a moderate speed, right at planing speed and your boat is lugging one minute and overspeeding the next, requiring constant movement of the throttle to counteract the "over reacting" of the boat, a prop change can fix it. As Wes stated, if your problem is a bow high attitude at a selected lower speed, then you may need both....trim tabs (hydraulic-adjustable for best control) and 4 blades of shallower pitch.

Alum props are for sale on ebay and you can get in and out for less than a hundred bucks per. If you are currently running such and are satisfied with them vs SS then no reason to change materials. With limited information furnished, I'd opt for the same prop mfgr-prop name if possible and go to 4 blades and drop 1" if possible or 2" if props furnished in 2" steps....just keep tabs on your RPMS when at WOT and stay within mfgrs. recommended RPM WOT band. This will get you into the engine control part of the problem for 200 bucks. Then if not happy, pursue Dole Fins or Whales Tails to be mounted on your engine's Anti-Ventilation plate just above the prop......which is another not all that expensive addition. If that fails, then invest in trim tabs.

 

[dazk14]

+1 with what Mark mentioned. Drop pitch and go 4 blade which will add quite a bit of stern lift.
Plenty of very sophisticated designed aluminum props available. We sell quit a few Solas Amita/Rubex 4 props with excellent results.~$118 iboats.
You should also look at engine mounting height, since the deeper the gearcase is buried under the hull, the more bow rise you'll tend to experience. 4 blades have excellent bite at higher mounting heights.
Also note, that motor will run very nicely WOT at 5750, which gives you more flexibility.
Good luck!

 

[jimmbo]

Trim Tabs are better option, as they don't force you to Compromise on Top Speed, it will still be there . A 4 Blade, unless the prop is Designed with Stern Lift in mind isn't going to make it plane at a lower speed, or keep it on Plane at said lower speed, though most boats are on a Clean Plane by 25 mph. Don't rev it past the 5500, point, it is already making less HP than it did at 5100 rpm.
With 21in pitch @ 5400m your speed should be in the mid to upper 40s. I am assuming 2:1 in the gear case. With 2 props you have a lot of Blade Area so slippage should not be Too High

 

[Faztbullet]

Tabs are the best option for the money and results...