newer engines, more power?

I have a 89 bayliner with a 50 hp force engine. I've been told in the past that this boat was made very heavy. The max hp on the plate is 50, which is whats currently on it. It struggles to pull a tuber right now with a fully loaded boat (3 x 150 lb passengers). Thats including the prop is the lowest pitch available. I was looking at newer 4 stroke engines and was wondering if they would have more power in general? What also confused me is that my engine only has 3 different pitch sizes available 10,11, and 12. The newer engine i was looking at, specifically a 50 hp yamaha had about 15 sizes of pitch ranging from 10 inch to 27inch. How would that new yamaha be able to push my boat with a 20+ inch pitch if my force can hardly do it with a 12 or 10?

Re: newer engines, more power?

It wouldn't. Horsepower is horsepower. Just because a wider range of props is available for one engine does not mean that engine can actually turn all of them to the proper RPM. That depends on the boat and other factors.

That said, many folks think that Force over-rated its engines. Beyond that, your engine has some years on it, and engine wear can cut down on the amount of power the engine produces. There could also be some other problem with your engine.

Also, your boat is almost 20 years old. It may have waterlogged foam, making it heavier. Your engine may not be mounted or trimmed for the best possible performance with that boat.

If the boat is rated for a max of 50 hp, you should expect it to perform well with that horsepower. Boat manufacturers are in the business of making boats that perform well, or they'd soon be out of business.

I'd think more about making sure your current engine is up to snuff and your boat is not heavier than it was when manufactured. I'm betting you'll get a lot more results in that direction than by switching brands of outboard.

What RPMs is your engine turning at wide open throttle (WOT). What is your speed at WOT? Those questions may provide a clue.

Re: newer engines, more power?

If repowering with a newer/different engine, compare the weight (lbs.) per horsepower for any motor considered. Four-stroke motors are significantly heavier than two-strokes with the same horsepower and extra weight is detrimental to boat performance. Good luck!

Re: newer engines, more power?

First the Force always rated there horsepower at the powerhead, not the prop, so it is a weak 50. also be sure you are not carrying, extra unwanted weight. saturated foam. a boat can easily hold and extra 500 lbs. bayliners of that vintage, are known for it.

Re: newer engines, more power?

While horsepower is horsepower, torque is what moves a boat. A 2 stroke 50 hp made today will have more torque than the one you have. And if you're comparing an EFI or DFI 2 stroke to your old carb'd motor, theres a world of difference in the way they accelerate.

Even the 4 strokes will probably pull better than your older motor. While they still struggle, generally speaking, with acceleration they have a lower gear ratio to help. And will be more efficient.

And since todays motors are prop rated you'll be gaing some anyway if yours was crank rated.

Re: newer engines, more power?

I've heard mention of water logged foam before. The boat has been out of water and completely covered up for over a year. So im assuming any foam should be dry, please correct me if im wrong though. Dry weight of the boat is around 1550 last i checked it. There is a 6 gallon fuel can which probably adds 50 pounds. Only gear i carry are some ropes, life preservers, fire exting, and a few other very small accessories adding no more than another 50 pounds combined. I don't know the WOT rpm as my boat/motor doesn't have a tach built in. I was thinking about investing in an after market kit to find out. According to the speedo on the dash it runs about 28 mph wot on plane with just myself in it and a 12 inch pitch prop. I assume this is close to accurate because i keep pace with the cars on the road, speed limit is 25.


"Four-stroke motors are significantly heavier than two-strokes"

I've heard that newer motors are lighter in general, with the newer materials out. Is this not true? I've always thought though that 2 strokes have a better power outtage because of the firing twice as often. I wasn't particularly interested in the 4 stroke either, i was using it as an example. I just need a better motor to push my boat and have no idea where or how to start looking.

Re: newer engines, more power?

While 4-strokes do tend to be heavier, the difference is negligible and doesn?t automatically correspond to higher speed for a 2-stroke of a given size. 4-strokes will push a given hull as fast as their 2-stroke counterparts in most instances, faster in many performance report comparisons. The weights in your size range are Yamaha 2-stroke = 189 lbs, Yamaha 4-stroke = 237 lbs, E-Tech 50 = 240 lbs, Suzuki 50 = 243 lbs. When you consider 54 lbs difference on a boat with total weight around 1400 lbs, the difference might correspond to 1 MPH. A good prop or a jackplate would produce a much larger performance gain than saving 54 lbs.

Re: newer engines, more power?

That old Force only weighed 160#....

Re: newer engines, more power?

Once wet, the foam will never really dry out, it just sits in the bilge and rots all the wood. The Yamaha prop may fit several different motors in different HP ranges, so they may need all those props for different applications.

Re: newer engines, more power?

ondarvr said:

Once wet, the foam will never really dry out, it just sits in the bilge and rots all the wood. The Yamaha prop may fit several different motors in different HP ranges, so they may need all those props for different applications.

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i know what your talking about now. I redid the front floor of my boat. There was no foam under it. The only spot i see foam is in the back next to the transom its like a hard orange styrofoam. Theres only 2 basket ball sized pieces (if that) and when i poke it with my finger its dry and brittle. Doubtful that its holding any water or adding significant weight. Apart from some possibly being next to my battery compartment under my seats soaking wet i dont see how that could add any more than another 50 pounds. I guess i should have mentioned this is only a 14' boat. Theres not much to it.

Re: newer engines, more power?

As some have said your problem may either lie in unwanted water or that force motor. Force motors were not well known for reliability or performance. They were not rated at the prop like others are so its not 50 HP at the prop and is a fairly weak 50. You'd be best getting a newer motor like a E-tec. The gas savings would be good aswell. E-tec is a 2 stroke but as efficient and puts out as muich pollutant as a 4 stroke (or close!).

Re: newer engines, more power?

Kev144 said:

As some have said your problem may either lie in unwanted water or that force motor. Force motors were not well known for reliability or performance. They were not rated at the prop like others are so its not 50 HP at the prop and is a fairly weak 50. You'd be best getting a newer motor like a E-tec. The gas savings would be good aswell. E-tec is a 2 stroke but as efficient and puts out as muich pollutant as a 4 stroke (or close!).

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hrmm. thank you for the advice. are all newer motors (all brands) rated at the prop?

Re: newer engines, more power?

vprgtsr001 said:

hrmm. thank you for the advice. are all newer motors (all brands) rated at the prop?

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As far as i know, yes. I know merc started to do it sometime in the mid 80's? someone correct me if i'm wrong. There is really nothing wrong with a good running force. It's just they werent very popular and are a bit underpowered. If your looking for a strong 2 stroke, you may be looking at either an Evinrude E-tec or Mercury Optimax. Four stroke there are alot from yamaha, honda etc. All make great motors.