1986 Outrage 18 Johnson 150

Optimizing the performance of Boston Whaler boats
VKR
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1986 Outrage 18 Johnson 150

Postby VKR » Sat Jun 12, 2021 11:07 am

[On a 1986 OUTRAGE 18, a 1986 Johnson 150-HP] outboard engine is mounted one-hole-up. The current propeller is an aluminum 14-1/2 x 19-pitch. With the 19-pitch propeller the engine can accelerate at full-throttle to approximately 5,500-RPM.

The OUTRAGE 18 is mainly for just general getting around Chesapeake-Bay-type waters and trolling speeds.

I may upgrade to a stainless steel propeller. Investigation on this site gives me confidence I am good with a one-hole-up [engine mounting height] and the 14-1/2 x 19-pitch propeller size. I also found a few people suggested the OMC SST II stainless steel propeller in the same size as a good stainless-steel option.

Prior to purchasing an OMC SST II stainless steel [three-bladed] propeller—if still available—is that still a good option?

Or, should I be considering some other propellers that are newer or have been proven-out?

jimh
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Re: 1986 Outrage 18 Johnson 150

Postby jimh » Sat Jun 12, 2021 12:58 pm

At the 150-HP power level, I am sure changing to a stainless steel three-bladed propeller like an OMC SST II would produce some improvement in performance.

There should be plenty 17-pitch SST propellers on the used market. They were the standard go-to choice for OMC engines. I expect you could buy a used one for $100 to $150.

Check the number of splines on the propeller shaft and the hub diameter of your engine. I think the SST propellers were available in several hub diameters.

ConB
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Re: 1986 Outrage 18 Johnson 150

Postby ConB » Sat Jun 12, 2021 2:23 pm

I have an 1987 Outrage 18 with a 1987 Johnson 150-HP mounted two-holes-up with a Michigan Wheel Vortex 19” aluminum propeller.

I could not make myself spend the bucks on a stainless propeller thinking the motor would die soon. Fifteen years later that has come true.

Con
!987 Outrage 18 / 2011 Yamaha F150
1969 13 / 30hp Johnson tiller

VKR
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Re: 1986 Outrage 18 Johnson 150

Postby VKR » Sun Jun 13, 2021 8:38 am

ConB wrote:I have an 1987 Outrage 18 with a 1987 Johnson 150-HP mounted two-holes-up with a Michigan Wheel Vortex 19” aluminum propeller.

I could not make myself spend the bucks on a stainless propeller thinking the motor would die soon. Fifteen years later that has come true.


I, too, kept my Johnson 150 crossflow running over the past eight years as funds were diverted to college education. Now, given the age of the boat and my reluctance to add 100-lbs to the transom with a modern outboard, I decided to rebuild the Johnson 150.

Although I looked into and found a reputable rebuilder, I'm currently doing the rebuild myself with the help of an outboard machinist-specialist that bored my cylinders .020" oversize. These engines are true workhorses, will take a beating, and have lots of life in them. This engine has over 1,00 hours prior to tearing it down. Of course, they drink fuel like crazy.

I'm optimistically planning ahead for a new propeller; the aluminum propllr is a bit dinged-up.

biggiefl
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Re: 1986 Outrage 18 Johnson 150

Postby biggiefl » Mon Jun 14, 2021 11:50 am

19" SST would be a good fit or see if Con wants to sell his since the engine puked.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

VKR
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Joined: Sat Oct 17, 2015 8:39 am

Re: 1986 Outrage 18 Johnson 150

Postby VKR » Mon Jun 14, 2021 10:43 pm

biggiefl wrote:19" SST would be a good fit or see if Con wants to sell his since the engine puked.

biggiefl, reading his post a bit closer, it seems he is saying that he never could decide on buying a stainless steel prop. He stuck with the aluminum one.

biggiefl
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Re: 1986 Outrage 18 Johnson 150

Postby biggiefl » Wed Jun 16, 2021 9:01 pm

I would NEVER run an aluminum propeller on an engine over 15-HP. The OEM OMC SST props are a good fit on those engines and can be found on E-Bay for $100-150.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

VKR
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Joined: Sat Oct 17, 2015 8:39 am

Re: 1986 Outrage 18 Johnson 150

Postby VKR » Wed Jul 28, 2021 10:29 pm

I just realized my 1986 Johnson 150 was mounted two-holes-up. I am getting ready to mount the outboard. Should I mount the outboard one hole up or leave it at two holes up?

Prior to the rebuild and using an OMC aluminum 14 1/2 x 19 prop, I would get some minor porpoising at higher speeds and and the engine trimmed out a bit.

[What is the] best [engine mounting] height for this 1986 Johnson 150 with a planned OMC SST II, 14 1/2 x 19 propeller?

Is it one-hole-up or two-holes-up?

Thanks

Blackduck
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Re: 1986 Outrage 18 Johnson 150

Postby Blackduck » Thu Jul 29, 2021 1:05 pm

The best prop for your boat was a Stiletto 14 1/4 X 17 stainless, engine mounted three-holes-up. The company is gone.

Jefecinco
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Re: 1986 Outrage 18 Johnson 150

Postby Jefecinco » Fri Jul 30, 2021 9:37 am

I believe Yamaha acquired Stiletto a few years ago. The recommended propeller may be available from Yamaha.
Butch

VKR
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Re: 1986 Outrage 18 Johnson 150

Postby VKR » Sat Jul 31, 2021 9:13 am

Blackduck wrote:The best prop for your boat was a Stiletto 14-1/4 x 17 stainless….


I have not purchased a stainless propeller. I will add the Stiletto 14-1/4 x 17 to my search.

[I seek] additional information and comments on the Stiletto propeller.

As mentioned in my earlier post, I [operate the 1986 OUTRAGE 18 boat with 150-HP Johnson engine] mainly on the Chesapeake Bay. I use the boat for trolling and general family use and enjoyment. While top end speed is nice, it's not my primary goal.

VKR
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Re: 1986 Outrage 18 Johnson 150

Postby VKR » Thu Aug 05, 2021 10:55 pm

The OEM Service Manual for the [1986 Johnson 150-HP outboard engine] specifies a "Full Throttle Operating Range" of 4500 to 5500 RPM.

What RPM should I be targeting with my propeller testing?

Currently, with two individuals on board and an old aluminum 14-1/2-inch x 19-pitch aluminum propeller [the engine can accelerate to a] top speed of 5,200 RPM.

Is that acceptable, or should I try and increase the top RPM?

jimh
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Re: 1986 Outrage 18 Johnson 150

Postby jimh » Sat Aug 21, 2021 5:24 pm

VKR wrote:The OEM Service Manual for the [Johnson 150-HP engine] specifies a "Full Throttle Operating Range" of 4500 to 5500 RPM. What RPM should I be targeting with my prop testing?

Generally the optimum propeller should allow the engine to accelerate into the upper range of the manufacturer's recommended full-throttle engine speed range. In this case that would be in the 5250 to 5500-RPM range for the engine.

VKR wrote:Currently, with two individuals on board and an old aluminum 14-1/2-inch x 19-pitch aluminum propeller [the engine can accelerate to a] top speed of 5,200 RPM.

Is that acceptable, or should I try and increase the top RPM?

Your report that the engine can accelerate to 5200-RPM puts the engine very close to the desired engine speed range for full throttle operation.

biggiefl
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Re: 1986 Outrage 18 Johnson 150

Postby biggiefl » Sun Mar 19, 2023 6:40 pm

I know it's an old post. I am running a 17-pitch SST propeller on my 115 Yamaha at four-holes-up and get a boat speed of 41-MPH at 6,000-RPM engine speed. If anyone thinks a 17-pitch propeller on a150-HP is acceptable they're insane or the OUTRAGE 18 boat has too much weight. A 150 should run around 50-MPH. I plan on a 200 or 225-HP for my re-power which should fetch me 57- to 60-MPH.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).