mounting outboard motor

[trasel]

C27 - Outboard motor mounting

This is my first post.
Black Friday (Nov 2011) I bought a 1983 27' Catalina on sale but later learned its inboard engine has low compression and won't start. (5411 Universal diesel)
Anxious to do some winter sailing, (I am on a mooring near Annapolis)
I purchased a used Honda 8hp long shaft outboard motor yesterday.
What type of transom mounting bracket should I buy and how deep should the prop be?
Will the outboard's prop interfere with the boats rudder on my off-center mount installation?
Thanks for any and all comments and/ or advice.

 

[Tim C350 April IV]

Outboard on a Catalina 27

The Catalina 27 that I had (1986, #6111) came from the factory with an outboard on a rack - offset to the port side. There was what looked like 3/4 plywood backing inside the transom - backing up the engine bracket mounting.

As you can see in the picture, the outboard had an extra long shaft, and if you look carefully, you'll see that we added a secondary mounting "block" to the outboard bracket - that set the engine back just enough so that it could be tilted full forward when sailing and get the entire prop and leg out of the water.

All in all, not a bad setup on the 27 - no slow prop hanging in the water, no heavy inboard engine and transmission stuck in the bilge. Need the engine serviced? Just back it up to a dock and get a friend to help you haul that 90 lbs off the boat and out to the car. Electric start was nice.

We had remote throttle and shifting - connected by cables that ran to a single lever control down at your feet on the port side. We'd taken off (or broken off?) the tiller handle on the engine, but that was OK because we never used it to steer the engine, and trying to reach back and mess with the throttle or shift was a pain. I got very used to not steering the outboard - it gave me plenty of practice for the next boat size up - where with the inboard engine, there was no messing around with trying to steer with the engine.

Lot's of memories.

Tim Brogan
April IV C350 #68
Seattle

 

[trasel]

Re: Outboard on a Catalina 27

Thank you for advice and excellent pictures! Do you think my 8hp will be enough power?
Was your backing plywood piece installed in the aft lazerette or located lower on the transom accessed thru the port lazerette rear access panel?

 

[Tim C350 April IV]

Mounting

The backing material needs to be in line with where the motor mount attaches. In the picture, you get a sense that it was mounted (bolted through) in the lower half of the transom. On my boat, I think that I had a removable floor mounted in the aft lazarette which would allow access to that area. I think the port lazarette (the deep one with the batteries in it) had a plywood bulkhead at the aft end. Since I had no inboard engine, I had this huge "attic" area, which I could crawl back through and get near that area as well.

I think the 8hp is in the ballpark. Some of it depends on the prop you install, some of it on the conditions you normally motor in (winds/current), most of it depends upon your expectation.

Good Luck!
Tim Brogan
April IV C350 #68
Seattle

 

[trasel]

Re: Mounting

Thank you again...that was a nice setup you had.
I will attempt a dry mount (no epoxy now/ too cold) with backing plate and maybe 6-8 bolts soon.
I probably will not be able to get my prop as deep as yours as you had an extra long shaft and I may run into issues with my pull start set-up too...oh well, its not rocket science, right?

 

[Jackdaw]

You got some great advice from Tim. I'd add that you might want to look hard at finding away to remote shift&throttle the OB. In its operating position the thing is going to be way below the top of the transom. It will feel like you are playing 'twister' trying to steer and work the engine while docking.

 

[trasel]

Thank you as well for your comments, as I really appreciate your advice.
I bought a $200 Garelick s/s springloaded mounting plate today with a 14 1/2" drop.
Mfg. instructions say to position cavitation plate 2" below water surface, but I want mine deeper so will probably have my cavitation plate around 6" below water surface.
Does anyone know any negative reasons why I shouldn't mount it 4" lower than what the mfg. recommends?

 

[Tim C350 April IV]

That puts the Power head of the motor 4" closer to the water when operating in lumpy seas. If the boat is hobby-horsing much at all in following waves, you run greater risk of dunking your powerhead.

Another thought - that ties in with what I mentioned above - is that you probably want to be able to raise the outboard clear of the water on both tacks - you're going to need to tilt it forward to do that. If the motor is too low on the transom, it might not have enough clearance when tilted forward.

Good Luck!
Tim Brogan
April IV C350 #68
Seattle