1987 SPORT 15 Engine

A conversation among Whalers
Rhetttaber
Posts: 1
Joined: Tue May 18, 2021 10:09 pm

1987 SPORT 15 Engine

Postby Rhetttaber » Tue May 18, 2021 10:34 pm

I have a 1987 SPORT 15.

Is there a recommended engine for a SPORT 15?

Recommended a four-stroke-power-cycle stroke engine.

[Older] two-stroke-power-cycle engines were lighter than four-stroke-power-cycle engines.

For a 50-HP engine, I have been told the four-stroke engine is nearly 100-lbs heavier than a two-stroke engine.

coachf
Posts: 8
Joined: Tue Jun 05, 2018 12:13 am

Re: Best engine for 1987 15’ whaler sport

Postby coachf » Wed May 19, 2021 1:28 am

My 2003 Mercury 50-HP FOURSTROKE weighs 246-lbs.
I have [a different boat that is longer and beamer and heavier than the SPORT 15 that is the topic of this discussion] a 1977 17-footer with tiller steering [as used by the] Campbell River [Lodge in British Columbia].

Near you which engine brand has the best dealer?

Near you which engine brand has the best parts?

Near you which engine brand has the best service?

[Mentions a] 50-HP or 60-HP four-stroke-powe-cycle engine or an E-TEC engine.

jimh
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Location: Michigan, Lower Peninsula
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Re: 1987 SPORT 15 Engine

Postby jimh » Wed May 19, 2021 10:13 am

A great engine choice for a SPORT 15 is a classic Yamaha 70-HP three-cylinder two-stoke-power-cycle carburetor engine.

biggiefl
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Re: 1987 SPORT 15 Engine

Postby biggiefl » Wed May 19, 2021 10:30 am

Yes a new 50hp can be roughly 100lbs heavier than an older 2 stroke. The boat handles 250lbs just fine and can handle more. Friend had a 90 e-tec on his with a hydraulic jackplate that probably weighed about 375lbs combined. I have seen quite a few 15's with V4 115's on them.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

roundle1979
Posts: 95
Joined: Thu Jun 13, 2019 11:10 am

Re: 1987 SPORT 15 Engine

Postby roundle1979 » Wed May 19, 2021 10:40 am

Similar thread here from 2017: https://continuouswave.com/forum/viewtopic.php?t=2870

If I were to buy a new engine, the Yamaha F70 would be high on my list.

I believe that the classic Yamaha 70 was around 230 pounds. The new Yamaha F70 (20 inch shaft) is 252 pounds.
Last edited by roundle1979 on Wed May 19, 2021 6:50 pm, edited 1 time in total.
2004 Nantucket 190 w/ Mercury Optimax 135

goldstem
Posts: 64
Joined: Thu Oct 29, 2015 12:57 pm

Re: 1987 SPORT 15 Engine

Postby goldstem » Wed May 19, 2021 11:01 am

Most [two-stroke-power-cycle 50-HP outboard engines weighed more than] 200-lbs. The exceptions were the early Mercury famous four-cylinder 500, the later three-cylinder 50 and 60 or 650, which were about 190-lbs with [power] trim.

The OMC 40-50-60 loop-charged two-cylinder engines were 200-lbs.

I have an 1988 Mercury 50. [Its weight is] nice and light.

ASIDE: My engine may be nearing the end of its life.

R DAVIS
Posts: 30
Joined: Thu Oct 22, 2015 10:33 am

Re: 1987 SPORT 15 Engine

Postby R DAVIS » Wed May 19, 2021 11:25 am

I installed a 2020 Tohatsu MFS 60, a 4 stroke 60HP engine on my 1982 Sport 15. This motor (with remote control) weighs 218 lbs. same as MFS 40 and MFS 50. Do not confuse it with the BRT 60 which is considerably heavier, and same basic motor as BRT 70hp.

The motor pushes my boat at 36 mph top speed and has a good hole shot for a four stroke. I'm very happy with this motor. These motors are probably more available than most new motors today. A Tohatsu dealer can tell you. They are also reasonably priced, a thousand to fifteen hundred less than the equivalent Honda and Suzuki motors.

jimh
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Re: 1987 SPORT 15 Engine

Postby jimh » Wed May 19, 2021 12:53 pm

roundle1979 wrote:Ditch your 3 quarts of two stroke oil (at around 7 pounds each) and you're at parity.


Oil does not weigh 28-lbs per gallon.

Oil floats on water. Water weighs about 7-lbs per gallon, thus oil must weigh less. Three quarts of oil must weigh about 5-lbs, so a quart of oil weighs perhaps 1.66-lbs.

Add the weight of five quarts of lubricating oil for four-stroke engines.

dtmackey
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Re: 1987 SPORT 15 Engine

Postby dtmackey » Thu May 20, 2021 2:32 pm

The 15 Whaler responds well to the Yamaha 70hp in both 2 and 4 stroke offerings.

I had the Yami 70 two stroke on my 15 and it has plenty of power and only weighs 225lbs. The four stroke Yami is 253lbs and I just mounted one on my Whaler with a hydraulic jackplate and hope to water test soon.

If you're interested, I have the following two strokes that will be for sale soon:

Yamaha 40 - oil injected, but no power trim
Yamaha 60 - power trim, but this is pre-mix motor (fully rebuilt)
Yamaha 70 - oil injected and power trim
Yamaha 70 - oil injected and powert trim
Yamaha 85 - power trim, but this is a pre-mix motor (fully rebuilt)
Yamaha 90 - power trim and oil injected

D-