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Repowering 1989 Outrage 18

Posted: Tue May 28, 2019 5:00 pm
by afinelli
[I have] been running my 1989 Outrage 18 with the 1989 Yamaha 150-HP two-stroke-power-cycle engine it came with when I bought it used about 10 years ago. This 1989 Yamaha 150-HP engine runs fine, but is not very fuel efficient.

The 1989 OUTRAGE 18 has mechanical cable steering that gets cranky from time to time.

[I do not] keep track [of engine operating hours] but [the engine is] probably run no more than 40-hours-a year, and it is used in protected mid-coastal Maine waters.

I may purchase a 2005 Yamaha F150TXRD with fuel injection from a reputable dealer at a very good price, and already set up with SeaStar Hydraulic Steering.

Q1: Assuming the 2005 Yamaha F150TXRD is in good running condition, is there any reason to be concerned about re-powering with this particular model?

Q2: is there concern about additional complexity of the four-stroke-power-cycle engine?

Q3: is there anything in particular to look for in a 2005 Yamaha F150TXRD?


Re: Repowering 1989 Outrage 18

Posted: Tue May 28, 2019 7:07 pm
by Phil T
There are dozens of Outrage 18 owned by forum participants that have been re-powered with a Yamaha F150. The F150 is a reliable and a good performer. Tp do winterization by yourself is easy.

Make sure you mount the engine at least two-holes-up from lowest possible position. (Top set of bolts in the third hole down from the top). You are going to want a 14.25" X 18 Yamaha Performance propeller installed.

If you have not already done so, take this opportunity to replace the fuel vent, fuel fill, and fuel supply lines with alcohol resistant hoses. Hamilton Marine carries them in stock in most of their locations.

Re: Repowering 1989 Outrage 18

Posted: Wed May 29, 2019 8:22 am
by jimh
afinelli wrote:This 1989 Yamaha 150-HP engine runs fine, but is not very fuel efficient.

If the present engine is running well, I don't see the need to replace it on the basis of poor fuel economy.

If your yearly operating of the boat is about 40-hours, and if the 150-HP engine consumes about 5-GPH on average, you are only consuming 200-gallons of gasoline. Let us assume you could cut in half your fuel consumption. This means you would save 100-gallons of fuel every year. Boat fuel costs are perhaps about $4 on the water and less on the highway. You maximum savings from fuel consumption reduction based on buying a new engine will be about $400 per year.

Your plan to buy a used 2005 Yamaha F150TXRD means you are buying a 14 to 15-year-old engine. You mention the price only as being "very good."

Take the "very good price" and divide it by $400-per-year to find the number of years of continued boating at 40-hours-per-year that will be necessary to repay the cost of the new engine. Then consider future maintenance and repairs on the four-stroke engine.

Old Yamaha two-stroke-power-cycle engines will run (seemingly) forever, as long as you provide them with good oil and reasonable care.

Now, if you have other reasons to want a new engine, and the 14 to 15-year-old used Yamaha fits your needs, then purchase it. However, be prepared to perform crankcase oil changes every year at the end of season. In Maine late-Fall weather, those oil changes may be a burden, and a bit of a sloppy task.

Re: Repowering 1989 Outrage 18

Posted: Wed May 29, 2019 8:25 am
by jimh
afinelli wrote:Q3: is there anything in particular to look for in a 2005 Yamaha F150TXRD?

Be vigilant for corrosion in the cooling system of Yamaha four-stroke-power-cycle engines from this era, particularly in engines used in saltwater.

Re: Repowering 1989 Outrage 18

Posted: Wed May 29, 2019 2:31 pm
by afinelli
I understand the economics of the fuel usage/payback concept and the beauty of keeping things simple with the two stroke that's running OK. One of the factors in re-powering is the desire to have hydraulic steering instead of cable, and although I'm told it's possible to do that on my 1989 150, for some reason it seems to me to make more sense to do that in connection with an outboard upgrade I can afford. Yeah, it's a 14 year old motor, but the 89 is 30 years old. Does that make any sense? Have to admit I'm on the fence. Thank you all for your advice. Your help is appreciated.

Re: Repowering 1989 Outrage 18

Posted: Thu May 30, 2019 10:13 am
by jimh
To invest in a new engine is certainly possible, even if the economics of the engine cost compared to saved fuel expenses are not justifiable. I have done exactly that, myself.

Hydraulic steering is a very nice improvement. If in this instance hydraulic steering comes as a bonus with the new engine at almost no extra cost, then even better to get the package deal. Of course, you will also need to get a proper helm pump, hydraulic lines, and perhaps bleed fittings to complete the new steering system. That will likely cost $600 plus installation costs.

Re: Repowering 1989 Outrage 18

Posted: Tue Jun 11, 2019 8:29 pm
by Malcolm Goodfellow
I have a 1988 Outrage 18 with a 2005 Yamaha F150 TXRD. [The engine] is strong and quiet. [The boat] came with an aluminum Yamaha 14.25 x 19 propeller, which I've been running. The engine mounting height was one-hole-up [when the following performance data was collected]. [Boat speed was] 47 to 48-MPH with one crew and 3/4-FULL tank of fuel at just over 5500-RPM engine speed, in calm saltwater.

The [above performance data] don't look right, that is, an aluminum propeller, a boat with bottom paint, engine speed 5500 rpm, mounting height one-hole-up.

The speed was acquired by GPS on many different days so [the engine] tachometer might be indicating below actual engine speed.

[The engine mounting height has been moved upward to be] two-holes up--where [afinelli] should be [mounting his engine].

On recommendation from Tom Clark, I have ordered a Yamaha 14.25 x 19 Turbo stainless steel propeller. The Yamaha Performance line is only available in even numbered pitched, the Turbo line in odd numbered pitched.

[Tom and I] believe the new propeller [when installed] and the change in engine mounting to two-holes up will [let the engine accelerate to] 5800 to 6000-RPM--the engine speed I'm looking for.

If not, I will be buying the 18 pitch that Phil had recommended [to afinelli in his comments in this thread above].

Re: Repowering 1989 Outrage 18

Posted: Wed Jun 12, 2019 8:54 pm
by jimh
I don't see how the new propeller will cause the engine to be able to accelerate to a higher engine speed. Generally a stainless steel propeller will create more load for the engine than an aluminum propeller when the diameter and pitch of both are the same.

Re: Repowering 1989 Outrage 18

Posted: Thu Jun 13, 2019 12:06 pm
by Malcolm Goodfellow
I am counting on only the higher engine mounting of 2 holes up to increase rpm. I didn't mean to suggest the stainless steel propeller would contribute.

Re: Repowering 1989 Outrage 18

Posted: Fri Jul 12, 2019 10:51 am
by biggiefl
It will probably counter the prop and keep you around 5500.

There is nothing wrong with buying a nice used engine. dealer can give you the hours on it and how it was run(what RPMS for how long). The old engine if in good shape may fetch more than you think as some people still desire the simplicity of older 2 smokes and their lighter weight. It will also help when you go to sell, especially since many lakes now have emission standards which would keep you from running on them. Lake Tahoe for instance banned older 2 strokes close to 15yrs ago. The silence of the 4 stroke is worth it in my opinion. Once you go quiet it is impossible to go back.

Re: Repowering 1989 Outrage 18

Posted: Thu Jul 18, 2019 12:55 pm
by biggiefl
Picked up my 18 today. Engine is mounted all the way up and has a SS 17 or 18" prop. I hit 5800 and honestly the 115 is not a bad match for the 18'. No GPS but seat of my pants says low 40's.