Prop on Evinrude E-TEC 50HP

[Nero]

On my new 26M I have a new Evinrude ETEC 50HP installed. The actual prop installed reads 13.75x13 (MacGregor recommends a 14x13" prop). Going full throttle with daggerboard und both rudders fully up, the GPS reads 14-15 knots and the engine is running at stable 5,000 rpm. Somewhere I read, that the engine (50HP) at full throttle should run at 5,500-6,000 rpm ant the speed should be higher. Is it the right prop ? Should the engine run at higher rpm and the 26M be faster ? Any ETEC 50HP experience on the 26M and comments very appreciated - NERO

[telwin]

You would prob want to change to a 14 inch by 10 or 11 pitch,if you can experiment with different size props the better,
I have a ss VENGEANCE 3 blade prop 14 inch by 12 pitch on a 50 hp mercury yr 2000 bigfoot with max speed of not more than 15 mph with the boat fully loaded plus ballast.
But you should also check with the etec guys on this board

[dennisneal]

Nero,

I have a 2006, 26M with a 2008, 60HP E-tec outboard. I have researched this issue a little bit. It may be important to know where you sail/motor; flat water inland lakes, or saltwater offshore, as the optimal setup might be different for each situation.

[noahvale]

The rule of thumb, at least with bass boats, is that you will gain 200 rpm per inch of prop pitch. You could go to an 11 inch prop and probably go to around 5400 rpm. That may or not be what you need for more speed. There is a trade off of power when you increase prop speed. It's something that can't be accurately determined without actually putting the new prop on. It can be an expensive experiment, with no guaranteed improvement.

[Kelly Hanson East]

Nero - in the literature for your engine from Evinrude there will be a "wide open throttle" range which is probably 5500-6000rpm.

This is the engine manufacturers statement of how this engine should be loaded so that when it attains fulls revs.

500 rpm low in this business is a significant difference and not one to ignore. If you usage is intended to be powering at 3/4 throttle or more, then you need to change this prop to get that WOT rpm into this range.

That being said, I am running a 14x11 on my Mercury EFI Bigfoot, which also only reaches 5000 rpm at WOT. I run above 1/2 throttle about 4 minutes each year, so I dont worry about being overpropped. YMMV.

[delevi]

My 50 Hp etec came with a 14x13 which would yield 5500 rpm at WOT with speeds ranging from 15-18 kts. I think of late, the engine is slowing down a bit and I top out around 5300 rpms. My Mac dealer who installed the engine (I bought new) said the 14x13 prop is ideal. Many things affect performance, i.e. sea state, current, wind, weight on board, ballast in or out. I loose about 4 kts when ballasted. High altitude is also significant. I mostly sail at sea level, but when trailering to mountain lakes i.e. Lake Tahoe, I change to a 14x11 prop. This makes a huge difference. When I tried it on SF Bay, however, my RPMs shot up to 6200 and speed topped out at 15 kts without ballast. I also recall the rule of 200 rpms per 1 point of prop pitch, but in my case the difference was much more than that. If you're not at high altitude, try motoring without ballst with one or two people on board and not much gear in calm water. You should see 17-18 kts boat speed. If not, I would get the engine looked at by a mechanic rather than investing in props. The size you have should be correct. As for reaching the ideal RPM range, I wouldn't worry too much. This is the same engine used in the etec 60 hp, just limited by the computer from attaining those extra 10 horses. Basically, the extra load shouldn't hurt the engine. This is just my opinion, however. I'm not an expert on engines. Hope this helps.

Leon

[Gazmn]

Welcome to prop wars

If you can humor a merchant to swap out props, perhaps 2 at a time, you can save some money - and not have 4 props like me

Anyway, a 14x9 or possibly a 14x11 Hydrus or big eared pontoon prop will do. However, double check that a 50hp Etec can swing a 14. I think it can, but confirm with a Mac owner.

The Hydrus line are aluminum props. My best prop - for me on my Very Fat Boat, is a 13.75x13 OMC SS I bought used on Ebay... SS props are stiffer and will spin higher revs than a comparable aluminum prop.

Good Hunting...