9.9 yamaha 4 stroke in Typhoon Sr. Well

[Moonshadow]

I have scoured the forum with many searches. I have not been able to get an answer to this question: Will a 9.9 Yamaha 4 stroke fit in the motor well of a typhoon senior? Thank you very much for any help you can provide.

[Chrisa006]

I don’t know if it will fit but it is way too much engine for the boat. My cd25 has a 6HP that is plenty without the weight making the stern squat.

[Moonshadow]

I have read that. I need the most powerful motor I can get that will fit in the well. Any advice would be greatly and sincerely appreciated.

The Yamaha 8 hp weighs the same. Why not go 9.9. The difference in wt. from the 57 pound 4 hp I have now and the 83-87 pound 9.9 is under 30 pounds. I solo sail 90% of the time. 30 pounds is less than another person in the cockpit. Also I have moved at least 30 pounds of anchor and other things to the bow area of the v-berth area to counter the extra weight on the stern... as stated before, any advice is appreciated.

[Sea Hunt Video]

Moonshadow:

In your search to determine if a 9.9 Yamaha O/B will fit in the motor well of a Ty Senior you might want to look at what those with a Cape Dory 25 have installed and their discussions on this board about size, tilting, etc.

The sailboats are admittedly different and it is probable the motor wells are different as well. However, it might give you some ideas on what size O/B would be doable on your Ty Senior.

There were 846 Cape Dory 25s built; only 57 Ty Seniors. You may have a greater pool of resources, information, ideas, size discussions, etc. I know there are several threads on O/Bs on a Cape Dory 25.

Just a suggestion; probably not very useful.

[Carl Thunberg]

Chris gave you some good advice for normal conditions. Maybe you need to start out by explaining your unique sailing conditions that requires such a large engine (which it is). You will find this Board to be very helpful once the contributors understand why something out of the ordinary needs to be done.

[Steve Laume]

Conditions where a great deal of horsepower would be beneficial: motoring into strong headwinds, motoring into large choppy waves, towing another vessel, powering off of a soft grounding, overcoming the effects of a fouled bottom.

Conditions where more horsepower will not be of benefit: any normal motoring, trying to push the boat beyond hull speed, overcoming an adverse current.

The second set of conditions are all interrelated, Steve.

[mgphl52]

Following Roberto's suggestion, just ask a CD25 owner for the basic measurements of the outboard well on CD25 and compare to what you have. You can also make some adjustments by altering/replacing the the pseudo-transom board.

[John Stone]

Well, the question is will it fit, not should I use an engine that large. Moonshadow, it’s a fair question but it’s likely no one knows the answer since it may well have never been done. I can’t tell you either.

I can tell you I’m a big proponent of doing what you want with your own boat. Though my boat is admittedly under powered, the Honda 9.9 High Thrust I use pushes the 18,500 lb fully loaded Far Reach at 5.9 knots at WOT and 5 knots at 3/4 throttle. Flat smooth water of course.

Keep in mind a short shaft 4 stroke 9.9 weights about 95-100 lbs and it’s a much bigger engine than a similar hp 2 stroke. it’s a beastly awkward and difficult engine to manhandle by yourself should you wish to remove it.

You might try a smaller engine (maybe you could borrow oneJ and see how you feel about it. A new 9.9 Yamaha or Honda 4 strike probably costs about $2,700-3000.

Let us know what you decide and how it works out. I’m always interested in new info.

[Moonshadow]

Thank you all for your time to reply. Thank you John Stone that is the question. Will it fit? Here is why I ask the question. As I stated before I want the most power I can get that will fit in the well. I moor my boat in a tidal creek that leads to a large river which leads to Charleston Harbor. I am faced with very strong river and tidal currents nearly all the time. I have limited "Windows" of time to sail and want to maximize my opportunities for fun. After all that is what it is about right?

There are times when wind and current prevent me from getting to the harbor which is only a mile away. I go up river instead which is limited by wind, port traffic, and draft restrictions. If I go up river I often have to buck wind and current to get back. Other times I can ride the tide out to the harbor and beyond but have no chance of getting back before dark. I have a 4hp mercury that pushes the boat fine in neutral conditions but works hard and is loud beyond comfort when working at WOT.

Here is the scene. It has been repeated many times. Get to boat at 3:00 pm... prep, and motor down the creek to the river. Head up river or down as conditions allow. Sail around for a couple hrs. At some point head for home.
If there is a 4 knot opposing current and my 4 hp pushes the boat at 5 knots that is 1 knot over ground speed. A knot is 1.151 miles per hour so for simplicity I will use mph. If I am 2-3 miles away and traveling at 1 mile an hour how long will it take to get home? Answer: A long time. (2-3 hrs) Mostly I do not mind going slow... that is why I have a sailboat and not a motorboat. However it turns out that, 2-3 hrs sitting next to a loud, headache inducing, vibration machine is not very much fun.

Many of us deal with this and it is part of coastal sailing. I get it. However, it is about making the experience as nice and fun as possible. I am thinking 8 hp or 9.9 hp Yamaha because they are the same size and weight, are two cylinders so run much smoother and quieter, and of course are more powerful so I will not have to work them to death just to make headway.

As before any advice is appreciated.

[John Stone]

Moonshadow
In theory of course your boat's top speed is limited by 1.34x the square root of the waterline length. So more horsepower won't make it go faster. But you are right that a larger engine might not have to work as hard to get there especially against a foul current or adverse wind.

I face the same issue sailing and under power in the Far Reach and our dinghy. I work as close to the shoreline as possible to get out of an adverse current. It's a big help when the hydrography allows it. I also, use the currents to my advantage which limits when I can go or where I can go but there is a great reward to pulling it off. I normally sail against current on departure and ride the current home to make sure I get back in time if the arrival time is a concern.

None if this answers the basic question you ask--will it fit. Maybe you can borrow one and see. I think the Yamaha 4 stroke is a little slimmer than the Honda but that is only an observation. I understand you can run a 2 stroke wide open with little risk of damage. Not so with a four stroke. Four strokes are quieter for sure. I still think a reduction gear and larger prop AKA the high thrust or power thrust are your best choice for you goals.

Maybe someone else will weigh in with more experience.

[mgphl52]

I fully agree with John regarding high thrust prop. I would look for a used one or, if need be, buy a new and try it before switching engines. You could solve the problem and save a several boat-units!

[Moonshadow]

I have a high thrust prop on my mercury 4 hp. It helped a great deal but not enough. I am looking for one to borrow to see if it fits but no joy so far. Have a great afternoon.

Thank you again for the time and effort.

Rich
Moonshadow
Typhoon Senior # 27

[John Stone]

Remember it not just the prop. A true high thrust outboard has a different gear ratio.

[Moonshadow]

Most of the cd 22 owners I emailed agreed that 4 hp was fine on a lake or in neutral conditions but was just not enough against heavy current. I mentioned it but maybe did not stress it enough, the prevailing wind in my sailing grounds is complementary to or opposed to the current. rarely do we have wind perpendicular to the current. Charleston, SC in the harbor and the surrounding rivers have narrow and congested navigation channels and lots of shallow water. In the end I am reminded of an old saying "There is no replacement for displacement".

I am thinking of working with a friend who cruises the Caribbean to pick up a 9.9 two stroke.Two strokes are smaller and lighter. Also, the new two strokes are cleaner and quieter than previous models but are not as clean and quiet as the 4 strokes. Maybe some one can tell it to me how the cow cuts the cheese.

RL

[John Stone]

In addition to the Honda powerthrust 9.9 extra long shaft we use on the Far Reach we also have a short shaft Tohatsu 9.8 two stroke we bought in the BVI two years ago. We used it on an inflatable. It's a great engine. We now use it on 14' alweld aluminum skiff. I guest it's about 60 lbs. It's about 2/3 the size of a similar short shaft four stroke. It's very fast. Runs good. Can be stored in any position. But it's louder than the Honda. It uses about 25-30 percent more fuel.

Good luck.