GUARDIAN 27 Re-power

Optimizing the performance of Boston Whaler boats
outrage 25
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GUARDIAN 27 Re-power

Postby outrage 25 » Thu Sep 29, 2022 2:31 pm

I am very happy because I bought a 1991 Guardian 27. The boat is beautiful, and it is without engines.

Based your first-hand experience with the GUARDIAN 27, give me suggestions for engines to buy for re-powering.

I may buy two used 2010 Yamaha F250 engines.

The seller advised me to fit twin 300-HP engines.

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Phil T
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Re: GUARDIAN 27 Re-power

Postby Phil T » Thu Sep 29, 2022 2:44 pm

The GUARDIAN 27 has a maximum power rating of 600-HP.

I recently piloted a 27 Cuddy and it is a BIG boat. With a hull weight of close to 5,000 lbs, It is a giant LEAP larger than a Outrage 25.

The boat I drove had twin E-TEC 300-HP engines and really moved.

Unless you need to reach a boat speed above 55-MPG, twin 250-HP engines will be good.
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outrage 25
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Re: Boston 27 Guardian Repower

Postby outrage 25 » Fri Sep 30, 2022 1:34 am

What will be the boat speed and engine speeds and fuel consumption for a GUARDIAN 27 with twin 2010 Yamaha F250 3.3-liter engines?

jimh
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Re: GUARDIAN 27 Re-power

Postby jimh » Fri Sep 30, 2022 8:30 am

At full throttle two 250-HP engine will consume about 45 to 50-GPH

If the boat speed is around 45 to 50-MPH, then the fuel economy will be around 1.0-MPG.

My good friend has a 25 WALKAROUND Whaler Drive, which is almost 30-feet long and 10-feet wide. With twin 250-HP engines his fuel economy peaks around 1.1-MPG. The top boat speed is probably in the 46 to 48-MPH range.

Jefecinco
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Re: GUARDIAN 27 Re-power

Postby Jefecinco » Sat Oct 01, 2022 9:22 am

My tendency is to install the maximum rated HP for a hull. People with sufficient power are seldom disappointed with performance. Complaints about under powered hulls are common.

Unless a boat is used for commercial purposes and gets a lot more than the typical 100 hours per year of recreational boat use fuel costs seem like one of the lesser costs of a year of boating. If fuel economy is an important factor in for person's boating budget going more slowly is an option.
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outrage 25
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Re: GUARDIAN 27 Re-power

Postby outrage 25 » Sat Oct 01, 2022 2:40 pm

The Yamaha engines that I would like to buy are shaft-size extra-long. I forgot to ask the most important question:

Are engines with Extra-Long shaft size the correct size for use on a GUARDIAN 27 with Whaler Drive?

jimh
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Re: GUARDIAN 27 Re-power

Postby jimh » Sat Oct 01, 2022 5:16 pm

The notatoin "Extra Long Shaft" means 25-inch shaft. For most larger boats a 25-inch shaft is the appropriate shaft length. Only the smaller Boston Whaler boats use a 20-inch shaft length.

Because the GUARDIAN 27 hull is not a recreational hull, I don't have any information on the shaft length. However, for many years outboard engines were only available in 25-inch shafts as the longest model. The appearance of 30-inch shaft engines seems to have been a more recent occurrence in the manufacturing of outboard engines.

outrage 25
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Re: GUARDIAN 27 Re-power

Postby outrage 25 » Mon Oct 03, 2022 10:00 am

Thank you.

Give me general instructions for assembling two engines in boats with the bracket.

I'm talking about height compared to the hull.

jimh
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Re: GUARDIAN 27 Re-power

Postby jimh » Mon Oct 03, 2022 1:22 pm

outrage 25 wrote:Give me general instructions for assembling two engines in boats...
Generally the engines are already assembled at the factory before they get to the boat. If you are seeking advice for how to install twin engines, please start a new thread on that topic.

outrage 25 wrote:...with the bracket.
What is "the bracket." I do not see any prior mention of "the bracket" so it is impossible for me to infer what you are talking about. Please explain more clearly and in more detail--in the new thread you will start on the topic of twin engines on brackets--exactly what "the bracket" refers to.