Installation of outboard motor on E27

[CWM]

Some notes on the outboard motor installation on my 1973 E27.

Photo 1: Cockpit view of one of the two upper motor mount backing plates.
Each is a 3" x 3" SS plate

Photo 2: View of the bottom of the transom via the port lazarette.
Shows the two lower motor mount bolts and the large washer used on one of them.

Motor is a new 8hp Mercury 4 stroke long shaft.
Motor mount is a Garelick Model 71091-101.


Other comments:
The 8hp outboard moves the boat very well.
I chose the 8hp model to keep the weight of the motor down.

The Atomic 4 was nearly dead, and the strut was broken when I purchased the boat in June of 2007.
During the July 2007 haul out, I disconnected the Atomic 4, and the yard only charged about $50 to remove the motor, which I sold for about $550.

 

[sleather]

Nice clean installation! Your choice of mounts is wise, and looks good w/ the Merc. When I upgraded my mount the 4 stroke model wasn't even out yet and went for the largest SS Garlick for my Honda 8(84#), no problems in over 12 years of use. You might want to consider adding a cleat either on the top of the coaming or inside on the cockpit liner. Tieing off the motor tightly while cruising takes a huge strain off the mount and also serves as a safety line for those events we cant predict.

One question, is there a spacer between the hull and liner for the upper bolts? The load on the upper bolts is extemely high and may deform the liner and compromise the caulk seal. I've had to reshim my rudder thru-bolt connections which work the same way on the E23(gap btwn. hull and liner).

Have you hooked up the power supply? I've got my Honda wired in but I'm not sure how much it really helps.

 

[CWM]

Steve:

Re: backing plate requirements for motor mount:
On my 1973 E27 there is a U shaped section glassed in between the transom and the aft end of the cockpit module.

However, the U shaped section does not extend to the hull, so the lower motor bolts are secured against the transom.

My Mercury motor does not have an alternator or electric start, so it is not connected to a 12v battery.

 

[JAS]

Looks like we did similar things. My mounting bolts are drilled through the transom and the nuts are visible in the cockpit. I did have to use starboard spacers outside to deal with the curve of the transom. My Yamaha 9.9 high thrust will make 6.2 knots with a bone in the mouth but 5.5 knot cruise is comfortable. I mounted a racor in the cockpit locker and with copper fuel lines connecting it to a bulkhead fitting I have no rubber hose inside the hull. A quick disconnect out side the hull makes removal or replacement of the rubber priming bulb a snap. You can see in the photo how I got the power cables through the transom, under the clamshell the cable is bedded in calk.

 

[CWM]

Addendum:

A question has been raised by private email about how I did the upper motor mount backing plates.

I drilled the two upper motor bracket bolt holes from the aft side of the transom fwd through the aft wall of the cockpit, then used a 3" X 3" SS plate as a packing plate on the fwd side of the aft wall of the cockpit.

You can see one of the SS plates below the power cord in the the attached photo:

 

[trumpmech]

same subject...just got a 1978 Ericson 27 with a blown Yanmar YSB8. So, eventually I want to replace the diesel with an electric motor just to get in and out of places quickly. I'm also going to mount an Evinrude Yachtwin 9.9 two stroke with electric start to the transom. After looking there is nothing structural back there and the transom looks to be very thin 1/4"? Any suggestions about how I go about either cutting a square in the transom to mount or just getting an outboard mount and offsetting to get some strength from the sides? Thanks

 

[wynkoop]

trumpmech my E27 has a very thick transom. I think it is about 1 inch thick or a bit more. If I were of a mind to bolt a mount onto it I would have no worries about doing that with through bolts and fender washers. Stainless of course and well bedded to keep water out of the wood core. Not sure what wood they used in the transom, but previous owner put an inspection port in the middle of my transom for some reason and the wood is not balsa. It is something much harder, probably marine ply.

I built a custom wooden mount to hold my trolling motor over the transom. The previous owner built a custom mount to hold a 5HP outboard in the middle of the stern just clamped to the transom like one would clamp an outboard. I used that and it worked well and the transom stood up just fine.

In my experience my little 39lb thrust trolling motor is good to get in and out of a marina. It seems to push the boat at about 2knots in calm water. I used it mostly to move the boat around when I was repowering and did not have a working inboard.