Backup Outboard

BigWeakSauce

Seaman
Joined
Apr 4, 2020
Messages
50
I have a 1974 Caravelle Chimera IV, 18' with a 165hp inline 6 Mercruiser. Weighs probably 3k lbs loaded up.
I repowered the engine but since its old I'm not thrilled about taking the family in open water, Lake Erie, with it.
I'm considering installing a small outboard, 6-9hp as a backup that can get me to shore in case my engine fails. Possibly toss it in the cuddy and bust it out if needed.
What is the minimum outboard hp I need to control my boat? I'm talking just enough to move the boat a few mph so I'm not waiting hours for a sea tow.
considering a trolling motor too which Im seeing about 60lbs thrust from a trolling motor is whats called for.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
A fairly heavy 18' boat will need a minimum of 15hp as an auxiliary if you want to actually go anywhere, even slowly. Less than that wouldn't even give you steerage. I had a 20hp on my boat (when I carried an auxiliary) and that was JUST enough..

Even as small as a 6 to 10hp is, it isn't something you want to be slinging around in a cabin and trying to hook onto a transom. Get a proper auxiliary mounting bracket, rated to about 20hp (as a minimum) and put your 'spare engine' on it ready to go. I would also be carrying enough 2 stroke oil to correctly oil your main tank at 50:1, and setting up a fuel feed line to run the auxiliary from the main tank. Even traveling just a few miles with a 15hp running at 3/4 throttle burns a LOT of fuel. The 20 litre tank provided with the engine isn't going to be enough for a 'long' trip. (and also something you don't want 'floating' around eating up floor space).

That's my thoughts.

Chris.....
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,620
I considered having a small OB on board when I had my single engine boat (24 footer), but the logistics were a bit overwhelming. Besides outboard's live by Murphy's law . . . :)

It is just a matter of keeping on your toes about your engine and being able to deal with issues that may arise. . . and having the GOLD level Sea Tow . . . They will come to you first :D

I waited 20 minutes for them once when I ran out of gas. :thumb:
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,296
a good long anchor line and a cooler of beverages to wait for your tow.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,413
So you’ve somehow managed to get to shore in someone’s back yard miles from your port of departure.

Now what?
 

JimS123

Fleet Admiral
Joined
Jul 27, 2007
Messages
7,952
I have a 1974 Caravelle Chimera IV, 18' with a 165hp inline 6 Mercruiser. Weighs probably 3k lbs loaded up.
I repowered the engine but since its old I'm not thrilled about taking the family in open water, Lake Erie, with it.
I'm considering installing a small outboard, 6-9hp as a backup that can get me to shore in case my engine fails. Possibly toss it in the cuddy and bust it out if needed.
What is the minimum outboard hp I need to control my boat? I'm talking just enough to move the boat a few mph so I'm not waiting hours for a sea tow.
considering a trolling motor too which Im seeing about 60lbs thrust from a trolling motor is whats called for.

A 9.9 would be ideal. Equip it with a steering rod so you can steer from the helm. More HP won't make you go any faster since the best you can do is hull speed anyway.

Just be aware that the kicker will get your out of danger and not necessarily get you all the way back home.

An electric "trolling" motor is not what you want.

I personally have had a kicker for 52 years now and won't go without one. But, on the other hand, its not because I repowered the engine or am concerned about by engine being old and in need of maintenance, its because its a needed safety item to cover unforeseen issues. There is no option to have a reliable, maintained engine.

BTW, my current 2700 pound 19 footer runs awesome with a 5 HP Sail Pro outboard on a Panther bracket.

Whatever kicker you end up getting, you must replace the prop with one that is suited for the application.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Yep, re prop it right with a less prop pitch for motot to run wot towards its max rpm range factory stated. Will need to throttle much less along pushing the boat much nicer at fast displacement speeds if encountering water currents, winds, different water escenarios, not that extreme though.

Happy Boating
 
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