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Repower 1979 Outrage V-20

Posted: Tue Feb 16, 2021 10:41 am
by Manfish
In the summer of 2020 I purchased a 1979 Outrage V-20 with a 1987 Johnson 150-HP engine. The engine was in rough shape and barely made it through the summer--as expected. The time to re-power is now.

I have a friend who is a Mercury dealer so I will be buying a Mercury engine.

Q1: what is the maximum or suggested maximum weight engine that can be installed on a 1979 OUTRAGE V-20?

Q2: should I install a jack plate as well?

I know Sal DiMercurio is very well versed in this topic and hopefully can help as well as others.

All help and advice will be greatly appreciated.

ASIDE: This is my first post on the forum at

Re: Repower 1979 Outrage V-20

Posted: Tue Feb 16, 2021 11:24 am
by jimh
Manfish wrote:Q1: what is the maximum or suggested maximum weight engine that can be installed on a 1979 OUTRAGE V-20?

Boston Whaler did not specify any limit on engine weight for boats made in c.1979. The best inference to make about an upper bound for engine weight is to infer the engine weight from the maximum horsepower rating, using the weight of an engine available at that time.

The c.1979 OUTRAGE V-20 hull is rated for 180-HP maximum. For more on this model see

1978–1985 Outrage V–20

If we look at that as allowing twin 90-HP engines, we then can look at the weight of 90-HP engines available in c.1979. For that information I rely on a collection of the weight of older outboard engines maintained here on continuousWave. From that collection I would guess that the OMC 90 V4 engine at about 300-lbs might be the heaviest allowed. This gives an inferred transom weight maximum of 600-lbs. However, I think powering with twin 70-HP might have been more common, and those engines would combine to weigh about 500-lbs.

Because 1979 is prior to 1983, I would infer that the horsepower rating at that time was in reference to the engine crankshaft horsepower, not to propeller shaft horsepower. The ICOMIA 28-83 standard for outboard engine horsepower was not in use then. In ICOMIA 28-83 the rated power measurement point is defined:

3.3.1--Power shall be declared as Propeller Shaft Power at the propeller shaft of engines sold with complete propulsion units, and at the couple to the propeller shaft of engines sold with reduction or reversing gears.

If we presume that there is perhaps a 5-percent loss of power in transmission to the propeller shaft from the engine crankshaft, then in terms of modern engines (which are all rated for propeller shaft power), the maximum power would then be 180 × 0.95 = 171-HP.

This gives new inferred limits on engine horsepower and weight of 170-HP and 500-lbs (at the most conservative) and perhaps 175-HP and 600-lbs (at the least conservative).

If your choice is to be limited to an engine made by Brunswick under their Mercury brand, then you would probably be limited to a FOURSTROKE or ProXS model.

The FOURSTROKE 175-HP and ProXS 175-HP both weigh 470-lbs (in lightest model) and should be a fit. Your friendly Mercury dealer can explain the differences between the two models.

I don't think you need to power the OUTRAGE V-20 at 175-HP to get decent performance. The PAU HANA, another OUTRAGE V-20 which is used primarily for angling, gets quite good performance from just 115-HP, hitting about 36-MPH using a plastic propeller.

Re: Repower 1979 Outrage V-20

Posted: Tue Feb 16, 2021 11:33 am
by jimh
Manfish wrote:Q2: should I install a jack plate as well?

The notion that a jack plate ought to be installed is somewhat hard to confirm. A jack plate offers a means to adjust engine mounting height after the engine is installed. It may allow you to tune the engine mounting height to optimum. However, the jack plate adds weight and mechanical complexity, along with possible loss of rigidity in engine mounting.

The possible gain is perhaps a slight improvement in ultimate top speed, perhaps 1-MPH or a bit more. The loss is clear in added weight, and there is possible loss in the added complexity. The jack plate also incorporates a small engine set back, which moves the engine weight farther from the boat's center of buoyancy, thus increasing any tendency for the static trim be down by the stern.

To me, a jack plate is most useful if the boat is to be used in extremely shallow water in routine operating, and reducing overall draft by raising the engine as high as possible would be helpful. However, in that application you probably would want a powered lift jack plate that can be adjusted from the helm and uses an electric motor or hydraulics to raise and lower the jack plate mechanism.

In short, I do not view a jack plate as a necessity.

Manfish wrote:I know Sal DiMercurio is very well versed in this topic and hopefully can help as well as others.

Sal DiMercurio has passed away. His many posts regarding the V-20 and other topics are preserved. You can draw your own inferences from what Sal wrote.

Re: Repower 1979 Outrage V-20

Posted: Tue Feb 16, 2021 1:19 pm
by Phil T
Welcome Manfish.

If you review the owner testimonial Sal shared, you will note this hull has a tendency to porpoise with heavy transom weight. When looking at engines, look at the comparative weights.
A jackplate should not be installed on this model as it increases stern weight.

Given the shallow deadrise, this hull does not require significant horsepower. As stated by Sal, a 200hp makes it to 60 mph.
I think a 140 or 150hp engine will be more than adequate for your needs.

Ensure your dealer installs the engine correctly and mounts the engine at least two holes up. A high quality stainless steel prop should be installed.

Re: Repower 1979 Outrage V-20

Posted: Tue Feb 16, 2021 2:24 pm
by Manfish
Wow. First, let me say how pleased and impressed I am with the quality (and quickness) of the responses I have already received from this community. And thank you jimh for showing me the proper way to structure my questions on CWW. I will endeavor to post properly in the future.

Next, the information provided thus far is invaluable and exactly what I was looking for. As a clarification to my decision on possibly going with a Mercury. The friend I referenced is the owner of the service company that works on my Pacifica 44 sportsfisher. He has become a Mercury dealer (although he does not advertise as such) to accommodate some of his clients with smaller boats looking for Mercury inboard and sterndrive motors. He has offered to sell me Mercury outboards at his cost, which is why I was leaning that way. Ironically, we had a Mercury 40hp on our 13' Boston Whaler in the 70's and 80's and we hated it (came with the boat) as it was constantly breaking down. We finally switched to a Suzuki and could not have been happier. Since then I have always run Yamahas or Hondas and had zero problems. My understanding is that the Mercurys are much more reliable these days. Perhaps that's not the case. I would rather go with a Yamaha (or possibly Honda) and I'm willing to spend the extra money to do so. I'm interested in hearing the opinions of the community. More importantly, how would that change the recommendation? Would I still be best getting the 175hp Yamaha, or should I go up or down on horsepower? I am on the West coast and operating in the Pacific, so the opportunity to run at 50+ knots is not realistic or desired. As a professional underwater photographer/filmmaker, my boat is often loaded with camera equipment that does not like being bounced around too much. When I'm fishing that changes, but I still don't need 50+ knots.

The advice to forego the jack plate is well explained and will be heeded and removed from consideration.

Finally, I'm very sorry to hear of Sal DiMercurio's passing. My sincerest condolences to all who knew him.

Again, thank you so much for your wisdom and advice. I'm looking forward to more conversations with this community.

Re: Repower 1979 Outrage V-20

Posted: Tue Feb 16, 2021 3:59 pm
by Phil T
The universal recommendation for a repower is as follows:

  • every brand currently has a decent, reliable and quiet outboard offering in the 90-, 150-, and 200-HP class.
  • choice is a matter of price, dealer service, and engine features.
  • get multiple quotes from dealers that lists separately the individual parts: engine, gauge(s) or display(s), keyswitch, harnesses, network components, shift/throttle cables, binacle, labor to remove, labor to install engine, rigging charge, water test, sales tax. If a dealer will not provide this, go somewhere else.
  • include a stainless steel prop ($500-800).

Re: Repower 1979 Outrage V-20

Posted: Wed Feb 17, 2021 12:34 pm
by jimh
Manfish wrote:...My understanding is that [Mercury engines] are much more reliable these days.

The recently introduced new Mercury FOURSTROKE engines from Brunswick seem to be excellent products.

I don't base this on my own experience with them--I have none.

I don't base this on anecdotal reports from others--there are very few for Boston Whaler re-powers and they are not particularly detailed.

I base my opinion of the career of David Foulkes--the guy who was in charge of their development about ten years ago. He became the president of Mercury and then the CEO of Brunswick. You don't get that sort of career as an engineer unless you engineer good products--well, at least, very popular and profitable products.

The only aspect of these newer engines that is a bit of worry is their size, but that seem unavoidable these days.

Re: Repower 1979 Outrage V-20

Posted: Wed Feb 17, 2021 12:43 pm
by jimh
Manfish wrote:... As a professional underwater photographer/filmmaker, my boat is often loaded with camera equipment that does not like being bounced around too much.

The OUTRAGE V-20 is a moderate V-hull design, but the deadrise angle is not particularly big. This will tend to give the boat more stability at rest and better resistance to rocking side to side than you would experience in a much deeper-V-hull with greater deadrise angle.

There really are no classic era Boston Whaler moderate V-hull boats that "slice" through headseas. If travelling into head seas, you should expect the bow to rise and fall rather than cut through waves.

As for operating in the ocean, I think most boaters do not go out into huge headseas. If they get out a mile and figure out they are going to be banging into big waves all day, they turn around and go back. The classic Boston Whaler OUTRAGE moderate V-hull loves to run on plane down wind and down sea, and will run on plane at a very nice speed, just a bit faster than the waves, and run over the top and down the front of moderately large waves without any bow steering or tendency to broach. Actually, running down wind and down sea in some big waves can be quite exhilarating and possibly even qualify as fun. So if you are out in the ocean and the wind comes up, you can get back to shore in a Boston Whaler classic OUTRAGE moderate V-hull boat without too much worry.

Re: Repower 1979 Outrage V-20

Posted: Thu Feb 18, 2021 8:38 am
by Don SSDD
Look at local boat dealers who are known to provide good service as a [method for making a] choice on [which engine] brand [to purchase]. Then pick a [engine horsepower rating] and a lighter weight in those brands.

I’m not knowledgeable on this hull but it sounds like you don’t need to max-out the horsepower based on the above recommendations.

If you have your known Mercury dealer providing good service, I’d lean toward a Mercury engine.

Re: Repower 1979 Outrage V-20

Posted: Mon Feb 22, 2021 7:17 pm
by steelhead55
[A report on a DIFFERENT HULL follows;}

I have the V-22 [a different hull design and different length] and a 225 Suzuki-Johnson four-stroke-power-cycle engine. This is a good set-up for ocean angling.

Re: Repower 1979 Outrage V-20

Posted: Wed Feb 24, 2021 11:02 am
by jimh
The REFERENCE article on the OUTRAGE V-20 hull shows the boat owned by Sal and the engine used: a 200-HP Evinrude FICHT.

The OUTRAGE 22 hull is quite different from the OUTRAGE V-20 hull. I would not make particularly acute comparisons between them.

An OUTRAGE 20 and an OUTRAGE V-20 also have very different hulls.