Re-powering TEMPTATION 2500 with Twin Engines

[mike]

I have a TEMPTATION 2500, and I plan to re-power. The boat currently has twin Yamaha 225-HP engines with carburetors. I consider the boat to be well-powered and not over-powered. In 2023, new V6 engines seem to be basically the same engines at power ratings of 225, 250, and 300-HP.

I have assumed that re-powering with more horsepower than twin 225-HP engines would a better choice on the basis that engines rated more than 225-HP would spend more operating time at a less taxing throttle and more efficient engine speed. The engine weight and engine price at my local dealer, as they would spend more time operating at a less taxing and more efficient RPM.

(Among the 225, 250-HP and 300-HP engines] the weight is the same and price is not different at the local Dealer.

I was told an in-depth thread exists in the Old Forum that documented an unsuccessful re-power of a 25 Outrage Whaler Drive boat with twin Yamaha 300-HP engines; I have not been able to locate that thread.

ASIDE: Jim, the latest search function has been great this year, Thank You.

Advice, or direction to the thread, is appreciated.

[jimh]

If I understand your comments, you are saying that the price charged by the dealer for a 300-HP engine is the same as he charges for a 225-HP engine. That seems crazy. Engine price is always a function of horsepower.

If there REALLY is no extra cost and no extra weight to get a 300-HP engine instead of a 225-HP engine, to get the more power engine does seem like an irresistible temptation (pardon the pun with the boat name).

You should consider the hull power rating, as I expect that at 600-HP you are going to be well above the manufacturer's rated horsepower.

[jimh]

I have assumed that re-powering with more horsepower than twin 225-HP engines would a better choice on the basis that engines rated more than 225-HP would spend more operating time at a less taxing throttle and more efficient engine speed, as they would spend more time operating at a less taxing and more efficient RPM.

I don't think you can really predict improved fuel econly with any sort of confidence. If you want a boat to move at a certain boat speed, a certain amount of horsepower is needed. Let us say that you plan to run the boat most often at a cruising speed that required 175-HP total.

The notion that you will get better fuel efficiency from two 300-HP engines running at a more reducedthrottle setting that produces a total of 175-HP than you will get from two 225-HP engines running at a less resticted throttle setting that produces a total of 175-HP is speculative. For every engine and every engine speed and load, there will be a particular overall efficiency at which fuel is converted into power. Engine efficiency is not a constant over the entire power range.

In modern engines with sensors and computer controls, getting more horsepower from the same physical engine block and all identical components if often just a case of allowing more fuel to be injected. While two engines might appear to be identical, there may be some subtle changes in components that are used in the higher power version.

[jimh]

I was told an in-depth thread exists in the Old Forum that documented an unsuccessful re-power of a 25 Outrage Whaler Drive boat with twin Yamaha 300-HP engines....

Here is an old thread about twin 300-HP engines on a TEMPTATION 2500:

https://continuouswave.com/ubb/Forum4/HTML/005922.html

In a quick browsing of that thread, the comment I found most interesting was this one:

He's had it to 71.4, but it still porpoises over 55

[Phil T]

The two main factors these days with a repower is price and availability.

In 2020-22, engines were backordered as long as 6-9 months. Currenly many dealers have loose engines in stock. The larger horsepower models are still not plentiful, so shop dealers. Availability could make your decision on which model to select.

[mike]

Thank you Jim, I think that thread is the one I was being directed to. [That thread has] great information. It shakes up my assumptions of the Whaler Drive.

My 22 Outrage has a closed transom and a single Yamaha Ox66 250 on a Custom Marine Bracket, I would have believed the WD was superior in every way.

Yes. the local Suzuki dealer sells any of the V6 engiones for the same price; 225, 250 or 300. I haven't take him up on it, and I don't think Suzuki would be my first choice.

Knowing my boat with 225-HP engines, I would tend toward twin 250-HP engines for a re-power. With the same price point, 300-HP engines would be hard to pass by.

I'm seeing a lot of 250-HP being taken off [replaced], so used engines may be the option.

At Marine Liquidators a Single Yamaha 450 was for sale this winter. That is no what I would do--but it did make me think

I appreciate the input. There is a lot to contemplate, especially since most of these options were not available when this amazing hull was built and designed.

[jimh]

[That thread has] great information. It shakes up my assumptions of the Whaler Drive.

I don't understand what information in that old thread you found to shake up your assumptions of a Whaler Drive.

I have a REVENGE with a Whaler Drive, and I really love the Whaler Drive. The ride characteristics are excellent, and the Whaler Drive is great as a swim platform.

[Jefecinco]

Professional fishing guides in the Gulf Shores and Orange Beach, Alabama area have been selecting Suzuki outboards for repower in preference of Yamaha outboards with more frequency than in previous years. I asked a guide what his reasoning was for replacing his Yamaha outboard with a Suzuki. He told me significantly lower pricing for the Suzuki, even with his guide discount, plus Suzuki's reputation for similar reliability were the major deciding factors.

This is not to infer that Suzuki engines are in any way superior to Yamaha engines or vice versa. It could simply be a factor based on dealers and engine availability more than anything else.

[mike]

I don't understand what information in that old thread you found to shake up your assumptions of a Whaler Drive.

I have a 22-footer with an Aluminum bracket and a 25-footer with a Whaler Drive. I love them both. I am a hardcore Boston Whaler, and I believe the Whaler Drive to be the ultimate engine mount with no downside. It is my experience and opinion, having owned one.

That thread had a bunch of criticisms of the Whaler Drive, and some reports that a bracket may have some benefits over our beloved Whaler Drive.

I just don't want to believe it.

[mike]

Professional fishing guides in the Gulf Shores and Orange Beach, Alabama area have been selecting Suzuki outboards for repower in preference of Yamaha outboards with more frequency than in previous years. I asked a guide what his reasoning was for replacing his Yamaha outboard with a Suzuki. He told me significantly lower pricing for the Suzuki, even with his guide discount, plus Suzuki's reputation for similar reliability were the major deciding factors.

This is not to infer that Suzuki engines are in any way superior to Yamaha engines or vice versa. It could simply be a factor based on dealers and engine availability more than anything else.

Totally agree. I said "I don't think Suzuki would be my first choice", but they are in close consideration. The economics are hard to argue.

I am brand-loyal and have a 1989 Yamaha 115 that is still running perfectly 34-years later with little more than service fo the water pump and carburetor rebuilding. Two generations [of my family] are still beating that engine exceedingly hard, all year round.

Also, I do missionary work in the Amazon and comfortably rely on a Yamaha Enduro 70.

[Jefecinco]

In the Amazon my goal would be to go for reliability over any other factor. I assume your Temptation is not there.

[jimh]

Mike--thanks for further explanation of your reaction to the article that seemed to downplay the Whaler Drive and promote using some other method of engine set back and bracket.

A lot of the Whaler-Drive-Not-So-Good thinking originated with Larry Goltz, who opted to use an Armstrong Bracket when buying a new OUTRAGE 25 in preference to ordering the boat with a Whaler Drive. As a general rule, people tend to defend their choices, once they have made them and implemented them in a manner that cannot be undone.

The main bug-a-boo found with a Whaler Drive is that it never gets completely out of the water, so the maximum speed of the boat is reduced. If you want to race your boat in very calm water against other boats and get the maximum possible speed, then maybe a Whaler Drive is not the best choice, but whoever does that sort of thing with a 25-foot Boston Whaler OUTRAGE hull? If you really wanted a super-fast boat you would not start with a classic Boston Whaler OUTRAGE hull.

But the fact that the Whaler Drive remains in the water is what helps improve the ride of a boat with a Whaler Drive. You just have to own one or run one for a few days to appreciate how differently that hull will ride with Whaler Drive.

Another possible factor in not opting for a Whaler Drive was the price. I think that by the end of the classic era the cost of adding a Whaler Drive to a standard OUTRAGE hull was about $6,000, which was a significant percentage of the boat price. That added cost was another dis-incentive to getting one.

[mike]

In the Amazon my goal would be to go for reliability over any other factor. I assume your Temptation is not there.

Definitely not on a Whaler in the Amazon.

[mike]

Q1: what are the real world downside considerations for using twin 250-HP or twin 300-HP engine to replace twin 225-HP engine that have carburetors and were two-stroke-power-cycle engines?

[jimh]

Q1: what are the real world [downsides] for using twin 250-HP or twin 300-HP engine to replace twin 225-HP engine that have carburetors and were two-stroke-power-cycle engines?

Liabilities:

• hull will be powered above manufacture rating;
• engine weight will increase, affecting static trim and ride, and exerting more strain on the Whaler Drive-to-hull connection, especially when the hull is out of the water and on a trailer, and especially if the trailer has to travel over rough roads;
• the added propulsion power will likely never be used because the engines won't be operated at full throttle for any significant amount of time in the actual operation of the boat; and
• the hoped-for improvement in engine efficiency by operating a more powerful engine under less throttle may not be realized.

Benefit: having a more powerful set of twin engines may allow the boat to be accelerated to plane and run on plane at a higher speed with just one engine in the event of an engine failure.