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Author Topic:   Auxillary engines
goldammerr posted 10-26-2001 03:34 PM ET (US)   Profile for goldammerr   Send Email to goldammerr  
I have a Boston Whaler Outrage 21 with a Mercury 200HP. Id like to install a small auxiliary outboard for safety. Any ideas on the specs for such installation, i.e.,
Long or short?
Proven retractable supports for the aux engine?


jimh posted 10-27-2001 09:38 AM ET (US)     Profile for jimh  Send Email to jimh     
Give some thought to the fuel situation with the two engines.

First, there is the question of fuel composition: are both engines using the same type of gas, i.e., either raw gas or pre-mixed oil and gas? It might be better to have both engines use the same kind of fuel.

Second, there is the issue of the auxillary engine as a back-up or redundant engine. If this is your primary reason for the second engine (as opposed to fishermen who want it for trolling all day at low speeds), then you should also consider having a redundant fuel system. If your main engine dies from bad fuel, your auxillary won't help you unless you have a separate tank of fuel for it.

Of course, the separate fuel system adds a lot of complexity to the back of the boat, and there's the issue of keeping the separate fuel fresh and ready for use if the auxillary engine is not run often.

goldammerr posted 10-27-2001 10:31 AM ET (US)     Profile for goldammerr  Send Email to goldammerr     
Thanks, havent thought of fuel considerations. The primary reason for the second engine is really back-up or redundant engine.


swede5 posted 10-27-2001 08:20 PM ET (US)     Profile for swede5  Send Email to swede5     
Goldammerr, I would be interested to hear what you decide to get for an auxilary outboard. I have a single on my 22 revenge and I'm considering something in the ballpark of a 10-15hp. I assume it should be a long shaft and would prefer a 4 stroke yet a 2 stroke fits the budget easier. Let me know.
jimh posted 10-28-2001 08:52 AM ET (US)     Profile for jimh  Send Email to jimh     
Another aspect of the auxillary engine is its steering and throttle control.

In an ideal set up, you should have a remote throttle control for the auxillary engine at your usual helm station. The steering of the auxillary engine should be linked to the main engine. The linkage should be arranged so that the steering works with either engine tilted up. For example, in normal use you won't have the auxillary engine tilted down and in the water. For emergency use you may want to tilt up the main engine to get its lower unit out of the water to reduce the drag.

See pages 10 and 12 for a look at how Louie Kokinis has installed his auxullary engine; it is a very nice set up.

If you are just going trolling with the auxillary, you probably don't need to go to these lengths. You can just start the engine, set the throttle, and steer the boat using the main engine (now off) as a rudder.

If you want the auxillary to be really functional in a "come-home" situation, you probably don't want to have to hang over the transom to start it, to set the throttle, and to steer it. Imagine you're out in rough weather and you have to spend an hour or two hanging over the transom running the auxillary. How are you going to see where you are going?

What about the power of the auxillary engine? You probably want enough power to keep the boat moving and manueverable in some fairly rough conditions. A couple of horsepower will get you underway in a calm sea, but will you have enough to move the boat ahead into strong winds and head seas?

If you follow this line of thinking to the end, you'll eventually decide you need twin engines. If you look at the difference in cost between buying a 200-HP main and a 9.9 HP auxillary or buying twin 115-HP engines, the results may be surprising.

Let's see how this works out. As a source of prices I'll use some "deep discount" pricing from a big Florida outboard dealer who had a Spring promotion this year:

Plan A: Main + Auxillary

200-HP Mercury EFI.....$9,500
9.9-HP Mercury EL......$1,750
TOTAL $11,250

Plan B: Dual Main

115-HP Mercury ELPTO..$5,500
115-HP Mercury ELPTO..$5,500
TOTAL $11,000

Pretty interesting outcome, isn't it?

Also, with twin engines, there are several advantages. If I do have trouble with one engine, I have plenty of power available in the second engine for making headway and manuevering. I might even have enough power to get up on plane and come home at 20 MPH instead of 5 MPH.

If I have engine problems, I have two identical engines, so I can use the good engine to help diagnose the problem with the bad engine. I can compare votage readings between the engines, exchange components between the engines, compare how they sound, compare how hot they run, compare their throttle settings. Having that second identical engine sitting next to the engine that has a problem is very helpful in locating the problem.

When I don't have engine troubles, I have some advantages, too. I get better boat handling at slow speeds with twin engines. I get better handling with twins at high speeds, too. The boat won't yaw as much, it probably will track better, it will be less sensitive to trim.

I may suffer a bit on fuel consumption with the twins at certain speeds compared to running a single, but when I want to go slow, as in NO-WAKE areas or trolling, I can shut off one engine and just run on a single engine. This saves hours on the engine not running, too.

You see, once you start thinking about have two engines, they start to make sense in ways you perhaps had not anticipated.


jimh posted 10-28-2001 10:51 AM ET (US)     Profile for jimh  Send Email to jimh     
Oops, I stacked the deck a bit in the above comparison by using a 200 EFI in one case and non-EFI 115's in the other.

To make it apples-to-apples, I should have used a Mercury 200L engine, which would sell for about $8,050 from that same source. That shaves $1,450 off the price of the Main+Aux approach, making it cheaper by about $1,200 than the the twin engine approach.

However, there are some major benefits to twins, and one that I failed to mention is the "cool" factor. That may be worth $1,200 in itself! :-)


andygere posted 10-29-2001 03:20 AM ET (US)     Profile for andygere  Send Email to andygere     
To follow Jim's thought on an auxiallary to get you home, what about a steering cable failure or an electrical failure or a throttle/shift cable failure? Mine is set up with a rope start, and tiller steering. I have a tiller extension so it's comfortable to steer and operate the throttle, and I carry a spare 6 gallon tank and extra fuel line in case of fuel system problems. It saved me once when the check valve in the primer bulb quit. Under normal use, it's fed off the main fuel system by its own hose. I have a 15 hp aux on my Montauk, which is probably more than I need. On the other hand, it will get me home faster in an emergency, and it weighs the same as the comparable 9.9. The only thing I don't like about my setup is the cantelever bracket it's mounted on. I'd prefer a long shaft clamped right to the transom. The motor bounces too much on the bracket in rough conditions.
andygere posted 10-29-2001 03:22 AM ET (US)     Profile for andygere  Send Email to andygere     
For the record, the cool factor is easily worth the $1200. There's just something about twin engines.
Louie Kokinis posted 10-29-2001 04:14 PM ET (US)     Profile for Louie Kokinis    
Twins vs single and a kicker has been a heated debate for a very long time.

I would suggest looking at your needs not the dollars before deciding. I've had both, and feel for my style of boating and fishing single with a kicker is the way to go. The only thing I miss is the sound of 2 synced motors screaming a WOT :(

Goldammerr: Mounting is probably the biggest problem with kickers on boats with a single engine design. Im assuming your 21 is a newer style with the transom designed for a single power. If this is the case, I would strongly recommend you go with a solid stainless bracket (not the retractable) since Ive yet to see a retractable that has withstood the test of time especially on a whaler. Your main challenge will be connecting the kicker to the main. Most products require you to hang off the transom to connect them - personally I cant see myself hanging off the back of the boat in 2-3 foot seas. Because the external bracket is going to be set back at least 8 from the main you will not be able to use the same system shown in my boats pictures.

Another problem you will face is keeping the motor stationary and in the up position while underway. Kickers are not designed to be in the up position while traveling so they tend to flop and bounce around all the time. The little piece of aluminum holding them in the up position is flimsy and is usually the second thing to go (after the bracket itself). We have overcome this problem by inserting a wedge and a separate tie-down to the transom to prevent the motor from bouncing and flopping around while traveling.

The next problem is fuel. My kicker has an independent fuel filter and pickup, which draws from the same tank as the main. If you do install the fuel line to the same tank, I would strongly recommend this system.

Size is probably the most important. Your boat has a minimum power rating of 135 HP. No secondary including a 115 will plane your boat! Every boat has a max displacement speed once youve reached it any power up to the boats min requirement is a waste.

Im assuming your boat is a newer 21 if its the older 21 with the open transom setup for twins your min power requirement is 150 HP. In this case I would highly recommend my setup and can email you details and more detailed pictures.

Swede5: The 15 works nicely on the 22 hull.

kingfish posted 11-03-2001 08:41 AM ET (US)     Profile for kingfish  Send Email to kingfish     
Roberto and Louis-

Just a passing note - OMC has a retractable bracket (or at least they used to - we bought this one somewhere between 5 and 10 years ago) that is really a tough, heavy-duty rig, with a compressed-gas cylinder to assist the lift from down to up. Has a very positive locking mechanism at both positions. I just took it off an old family boat we just sold and installed it on our new 25' unwhaler for a 9.9 4s Yamaha kicker for a 225 Yamaha. It has about 8" of travel which in this application, when I mounted the kicker and bracket as high as I dared to still get bite when the kicker is operating, leaves just the skeg and about the lower 1/3 of the kicker prop in the water when idling. So, the kicker prop spins just a little (in neutral) when slowly underway with virtually no impact on steering or anything else, but once up on plane there is mucho clearance, and we're able then to leave the kicker in the vertical position all the time. (For us, the same bracket but with 10" or 11" of travel would be perfect.)

I'll be installing a kicker on my Outrage 22 this winter and I haven't decided yet just which way I'm going to go; all I know at this point is that it appears one of my lifting eyes is right in the way of whatever I do...


kingfish posted 11-03-2001 09:26 AM ET (US)     Profile for kingfish  Send Email to kingfish     
Adjust previous post (I just went out and checked): the travel is about 11-1/2" and I wish it was 13" or 14".
goldammerr posted 11-14-2001 08:24 PM ET (US)     Profile for goldammerr  Send Email to goldammerr     
A dealer told me its a waste of money to try anything higher than 10hp for the aux engine; difference in speed is negligible. Sounds strange to me, the boat should have an improvement in maneuverability + speed, although I do understand the boat will not get into a plane with a 10, 20 or even 40hp. Any thoughts on this?


jimh posted 11-15-2001 12:50 PM ET (US)     Profile for jimh  Send Email to jimh     
The dealer's recommendation to limit the auxillary to 10-HP is one that I would agree with. You want the engine to be running at a reasonable crankcase speed so that it can develop the horsepower, and you want it turning a fairly large diameter, small pitch prop, so that it can develop thrust. Often manuafacturers make a 9.9-HP engine for use with sailboats that is geared and propped accordingly, as opposed to an engine designed to plane small fishing boats.

Even a 70-HP engine would not plane your boat. You'd be stuck running at the same speeds you could get from a 10-HP engine.

dfmcintyre posted 11-15-2001 01:11 PM ET (US)     Profile for dfmcintyre  Send Email to dfmcintyre     
Following what the other posts have stated, I had a 9.9 Merc _available_ to mount when needed on my 22 Outrage. At time when we had crossed Lake Huron at the wide section, I also brought along the 9.9.

Jim's correct in not bothering with anything above 8 - 10hp. Just gets heavier, with no speed increase.

When we towed the boat up to where we launched, it just sat on some carpet on the cockpit deck. When launched, I just attached it to the port side of the larger Merc. No steering / throttle / jack plate.

Never _needed_ to use it (Murphy's law.....), but I tried it out a few times.

The most important thing I did was to tie off the handle so it was pointing straight ahead, and crank in about 3/4 throttle. Then I could steer using the "dead" larger motor. Naturally, you would have to be back at the aux when entering a harbor, but this setup is kiss simple.


Tom W Clark posted 11-15-2001 01:29 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
I concur with the opinion about a 9.9 being enough. A boat that cannot get up on plane is pretty much going to be limited to its hull speed which is dependent upon waterline length. Once a boat is at hull speed it will take a huge increase of thrust beyond what there is already to get the boat to begin climbing its own wake and go into semi-planing mode.

I know from experience that a Montauk's hull speed is about 7 mph. This can be achieved with a 6 hp and perhaps even with a 4 hp. Certainly, a 9.9 is overkill on a Montauk. An 18-Outrage is nicely propelled by an 8 hp or a 9.9 (I've run both on mine).

Now having said all that, there are some exceptional circumstances that might warrant a larger auxiliary. If the auxiliary if for safety, then one could argue the need for a motor more powerful than necessary to achieve hull speed if it is imagined that the motor may be needed in, say, a storm where the wind is really blowing and it's not speed so much as control that is needed.

Another very odd scenario is what the original owner of my 1983 18-Outrage used his boat for. He had a Johnson 15 on the boat with a normally pitched prop (i.e. like if the 15 were on a skiff). The boat had dual binnacle mount controls and a steering tie bar for full control of both motors from the console.

He did a lot of fishing and used the kicker for trolling but he moved around a lot while fishing from one spot to the next. Instead of shutting down the kicker and tilting it up and then reversing this procedure each time, he would simply start the big motor, give the kicker full power and add just enough power to the big motor to get the boat up on plane. The tall pitch of the prop on the kicker prevented it from over revving but also allowed it to achieve full throttle rpm. Since this motor was used mostly for trolling, it kept the plugs from fouling and just gave the motor some exercise. He was also able to cover a lot of ground relatively quickly and easily.

After I bought the boat (and it was stolen and recovered without the motors) I repowered with a 9.9 hp. The 9.9 and the 15 were virtually identical motors and I didn't see the advantage that the original owner did. I also came to realize the dual binnacle mount controls were not as great as they seemed. In the course of ten years of ownership I used an 8 hp Yamaha for two seasons and this motor worked as well or better than either the 9.9 or the 15 for my purposes.

Kingfish is right about the OMC brackets. They are the best, but not cheap. As much as $400 but they can be bought used (just make sure the cylinder is still good). I bought one last summer for $100 and completely rebuilt it with all new stainless bolts, nylocknuts and bushings as well as a new varnished mahogany mounting block. Good as new.

Kingfish, the stern lifting/towing eye problem is a common one. One my boat I removed the offending eye, patched the hole and remounted the eye between the motors. (I.e. I moved it about 6 inches closer to the center line of the hull. The kicker covered the old hole so the patch didn't even have to look good, though, of course, mine did.

Louie Kokinis posted 11-15-2001 01:46 PM ET (US)     Profile for Louie Kokinis    
I agree with the 9.9 being more than enough.

The only reason I put the 15 Big Foot on mine was the transom thickness - a 9.9 wouldn't fit without cuting the transom :(


lhg posted 11-15-2001 02:04 PM ET (US)     Profile for lhg    
BW, in the "good ole days" always recommended bolting the Aux engine (mandatory 20" shaft length) directly on the transom, whether it be a Montauk or V series Outrage. The system of operation Don McIntyre recommends is also BW's method. Solid, reliable and simple. While running on the main engine, the aux must be strapped back against the boat so it won't pop off the full tilt stop lever.

The aftermarket pony motor lift brackets are simply not recommended for severe duty when the going gets tough, which is exactly when you need one of these installations to perform. The aux has to be a rock-solid installation in all conditions, whether it's being run or just riding along tilted up.

A dual engine throttle control is a very nice way to connect one of these, however. One control for the main engine, and one control for the Aux. This can be accomplished with either 2 single controls side by side, or one dual control, which I think looks best.

Kingfish - Maybe you could solve your lifing eye problem by using a set of Springfield Marine 10" setback transom jacks, like I have on the 18, and like Backlash and JimH (soon will) have. Put the main engine on one, and the aux on another. For the smaller engine, the jackplate could probably be modified (notched) around the lifing eye.

Tom W Clark posted 11-15-2001 02:19 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
lhg, you are absolutely correct about bolting the kicker directly to the transom of a Whaler. A far superior and simpler arrangement. My comments about the OMC bracket were general comments only. The bracket I have is on an old wooden boat of mine with an I/O where that is the only solution.

Kingfish should clamp and bolt his kicker right to the transom. A setback plate will move the weight of the kicker that much further aft and thus put that much more strain on the transom as will as make it harder to reach. Moving the eye bolt will only involve drilling one new hole in his boat while a jackplate will mean at least four new holes.

lhg is also correct about securing the kicker while in the up position. The lock which holds the motor up is not designed on any small outboard that I know of to withstand the pounding of even a moderately choppy run. I know, I promptly sheared the mechanism off the 6 hp on my Montauk the first time I ran it in chop.

The best solution, at least for the OMC motors, is to buy what they call (or used to call) a trailering bracket. It was designed to support the motor in the up position while trailering. It was simply a continuous stainless steel rod formed into a bracket that replaced the tilt pin on the motor. It formed a sort of squarish hoop that when flipped up allowed the tilt lock mechanism to grab hold of it in the up position and lock it in place, preventing any bouncing whatsoever.

This part used to cost $20 and was well worth it.

andygere posted 11-16-2001 11:45 AM ET (US)     Profile for andygere  Send Email to andygere     
I have the OMC bracket on my Montauk as well. Like Tom, I rebuilt mine by replacing all the bolts with stainless steel, replacing the bushings and refinishing the plywood mounting pad. Unfortunately, most of the bolt/bushing holes are ovalized too much and the new bushings were almost immediately trashed. The Whaler Dealer in Alameda CA is an old OMC shop, and the parts guy there assured me that he can still get parts for these brackets, so that's my next move. There is a heavy duty version designed for 4-strokes made by OMC that's still available, but it runs about $500! My current solution is to keep the motor tilted down, but lifted on the bracket when running. It does spray a little water in the cockpit, but otherwise does not hurt performance in any significant way. When drift fishing the cavitation plate makes an annoying splash with every swell, so I tilt it clear until getting underway again.

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