Rudder mounted electric thruster on E-25

Mblace

Member I
I bought an E-25CB a while back, and am almost done going through it. It came with an older Evinrude 10HP 2-stroke, but the idea of hauling around a 95# stink bomb on the stern and can of smelly gas in the cockpit is a major turn-off, especially since I will likely only use it for maneuvering on/off mooring. If I did use the outboard, I can’t imagine trailering with it mounted, but having to get it on and off the transom (which shows web cracks from the motor having been mounted) looks to be near impossible without a hoist. I recently saw that Torqueedo has a rudder-mounted electric pod drive married to a Hanse 35 - looks like an interesting concept. I can get a 150# thrust (about 4HP equivalent) electric trolling motor and a couple 100AH lithium batteries for less than $1500. My thought is to adapt the trolling motor drive pod to fit on the back of the rudder a couple inches from the bottom, with the motor and wiring faired into the rudder, and the controller in an enclosure on the transom and speed and direction switch on the tiller. I plan to beef up the rudder gudgeons, so I don’t see any issues related to stress. Call me crazy? Has anyone tried this? Suggestions? I have all the tools and materials at hand to do the work, just not sure it’s a practical idea.
 

peaman

Member II
Converting to electric to discard an old 2-stroke outboard sounds like a big improvement. But the idea of pushing a boat with the rudder is not at all appealing. I think a better arrangement would be to use an electrically powered prop similar to how outboards are applied: by pushing on the transom, and with means to pull the prop, etc out of the water when under sail or at the dock.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
I am also a bit leary of the forces added to the rudder and pintles. First, how about trying a larger (borrowed? from a fisherman friend?) electric trolling motor mounted on the conventional place on the transom just to see how it functions?
 

gabriel

Live free or die hard
Are you still planning using the rudder raising system? Where on the rudder would you mount? Inline with pintle? Also what advantage is to be gained by this setup over just clamping to the transom cutout which is a decent motor mount itself.
 

Mblace

Member I
I had 3 goals in mind 1) eliminate the heavy, smelly and clumsy gas outboard, 2) eliminate having to manage 2 different steering vectors when under power, 3) maintain the full functionality of the rudder - both the raising feature and removability for trailering. I had hoped to have a light, clean, low-drag source of propulsive power that can be used to steer and propel the boat around the mooring but not for cruising any distance - there when needed but transparent when not in use. Electric motors freewheel when not powered. I was planning to mount the pod just above the sole of the rudder, just enough to protect the bottom of the prop - that way the pod and prop will always be below the waterline. But - your suggestions to use a portable electric drive would have the added benefit of being able to use it on our tender dinghy when at anchor or a mooring buoy. Plan to use it at my son’s place in Maine - it’s waterfront near Gouldsboro (Taft Point) but no dock yet...

This all started when looking at upgrades to the 2-stroke. 4-stroke gas outboard? How big - they’re all heavy, even lower power motors (at least 70#) and expensive. Mount on a kicker? Electric outboard? Expensive, and still have 2 tillers for maneuvering. Trolling motor? Torqueedo says its 5hp electric is functional for up to 6000# boat. Most folks on the forum say at least 8HP. Seems everything requires compromises/tradeoffs.
 

olsenjohn

John Olsen
Blogs Author
I own an E25 CB and would be skeptical that the small electric equivalent to a 4 or 5hp would have enough thrust. I am sure it would slowly get the boat up and moving in calmer waters, but stopping it in a timely manner is another story. I had a 6hp outboard on mine and it was unable to provide enough thrust to stop the boat coming in to a dock without really slowing down to a crawl and having a lot of pre-planning. It churned a lot of water, but did little to bleed off the momentum. I bought a 9.9 high thrust Honda and have been very pleased with the level of control it gives me over the boat.

I love the concept of an electric. Just not sure you will have enough thrust for docking maneuvers or high winds out on open water.
 

gabriel

Live free or die hard
For getting in and out of a dock, my opinion is that the 4 hp torqueedo is plenty and probably excellent option for that...

I use the 8hp Johnson 2 stroke (love it my only complaint is it consumes to much fuel) that came with my boat and I find 8 hp to be more than enough to power my boat in my area...so much so that the day I need to replace it, I’ll replace it with a 6 hp 4 stroke (keep same size and weight of the old engine) and I think I’ll be fine other than the extra vibration from losing a piston.

tides and currents aren’t much of a factor here in Southern California though
 
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