275 or 26 CONQUEST with Twin Mercury 150 FOURSTROKE

Optimizing the performance of Boston Whaler boats
Elfwerks
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Joined: Fri Feb 21, 2020 1:03 am

275 or 26 CONQUEST with Twin Mercury 150 FOURSTROKE

Postby Elfwerks » Fri Feb 28, 2020 10:10 pm

Greetings all. We have a 2001 Conquest 26 and will re-power soon. I've searched extensively without success here and elsewhere for performance data regarding twin Mercury 150 FOURSTROKE engines on a Conquest 26 or 275 Conquest-–same hull as I understand. While minimum recommended power on our boat is 400-HP, in 2001 that was achieved via Optimax twins. Some boaters with Mercury Optimax 200-HP engines have re-powered with Mercury 150 FOURSTROKE engines with little performance lost, likely related to identical 3.0-liter displacement. I am familiar with performance reports for the Conquest 255 with twin VERADO 150 engines, however the hulls are significantly different by 1,300-lbs and about a foot of beam; Conquest 255 with a dry weight of 4,900 pounds and 8-foot 6-inch beam, Conquest 26 with a dry weight of 6,200 pounds and 9-foot 7-inch beam. Also, the 150 VERADO and 150 FOURSTROKE engines are significantly different in how they deliver power.

Thanks ahead to anyone providing data on a Conquest 26 or 275 Conquest re-powered with twin Mercury 150 FOURSTROKE engines.

Ben

jimh
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Location: Michigan, Lower Peninsula
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Re: 275 or 26 CONQUEST with Twin Mercury 150 FOURSTROKE

Postby jimh » Sat Feb 29, 2020 5:25 am

I can’t offer any first-hand experience with your boat or the particular engine choice. However, I do recall the considerable excitement that accompanied the introduction of the 150 FOURSTROKE engine, the first Mercury-made non-supercharged 150 model. Some initial reports of those engines in re-powering a classic Boston Whaler hull were fantastic, and I mean that also in the sense of fantasy. One report in particular gave boat speed data for the 150 FOURSTROKE engine on a 22-footer that previously could only be achieved with a 225-HP engine. And fans of Mercury were immediately announcing that there would soon be higher power models introduced on the same block. There seems to a belief among some boaters that the true power of a Mercury outboard is always much higher than the cowling decal indicates. I don’t believe Mercury introduced any higher rated versions.

I believe the Mercury 150 FOURSTROKE has been a great engine for Mercury, but I don’t believe it is really a 200-HP engine in disguise. In the modern day world of EPA regulation on exhaust emission based on actual horsepower, I think an engine sold as a 150-HP is going to make 150-HP, or perhaps a bit more. Also, engine price is highly correlated to engine power, so I doubt you’d get 50-HP extra for free.

Elfwerks
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Joined: Fri Feb 21, 2020 1:03 am

Re: 275 or 26 CONQUEST with Twin Mercury 150 FOURSTROKE

Postby Elfwerks » Sat Feb 29, 2020 12:24 pm

Thanks very kindly for your input and care with the forum.

Sincerely,
Ben

jimh
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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: 275 or 26 CONQUEST with Twin Mercury 150 FOURSTROKE

Postby jimh » Sun Mar 01, 2020 5:27 am

Now with many, many performance reports for the 150 FOURSTROKE published, you should be able to get a real-world assessment of the engine.