outboard dillema-need advice

[Nicky17000]

Hello everyone.
The Nissan 9.9(2stroke) gave up its life and now I need to replace it before the summer ends.(Here it is unwise and unsafe to sail without a reliable engine.)
I went to see what's available in my area and the best options seem to be between Tohatsu 9.8 and Tohatsu 6 sail-pro. (both 4 stroke)
I'm going crazy because I can't decide between the 2.
According to the seller, one would be slightly less powerful and the other slightly more than my previous motor.(they don't sell the 8hp model because it is only10euros cheaper than the 9.8)
The 6 is specifically intended for sailboats with extra long shaft and high trust propeller and being one cylinder is 10 kilos lighter than the other.
The 9.8 does not charge the battery but it is 2 cylinder and only costs 250euros more.
The boat is Hunter23.5(water-ballast)
The old motor, we used it mainly at half trottle.
My main question is-would the 6hp be enough and efficient to drive in a cross-current?

 

[Joe]

6 hp is plenty... I'd get the lighter one. If I was going to get the 9.8 I'd splurge and get electric start ..... way, way more convenient... and I'd get the remote too. Otherwise the lighter the better. The 9.8 will accommodate any type prop you like.. just tell the dealer you want a hight thrust prop and have him change it out. They're all the same price.

 

[Rick Webb]

The Six is Plenty Powerful Enough

I'd be tempted to go with the eight for the extra cylinder, can they not get it or is it just not stocked?

 

[Nicky17000]

Re: The Six is Plenty Powerful Enough

Hi Joe and Rick,
I was leaning towards the 6 because of the lighter weight. I used to service to old 9.9 on the transom because it was too heavy for me and a hassle. On the other hand I'm still a bit scared about the pushing power of the 6.
The 8hp model is not stocked because it is never requested since it is basically the same as the 9.8, only the carburettor is different, even the same weight. So for only 10 euros, people choose the 9.8.

 

[bruce1309]

I ran my H26 with a Tohatsu 9.8 four stroke that replaced a 10 hp two stroke. It pushed us along just fine at 5 kts with power to spare. I think the 6 hp will work just fine. The four stroke is, in my humble opinion, 20% more powerful than the same size two stroke. I couldn't ever prove it but it just felt that way.

 

[wonkodsane]

The 6hp, bigfoot style is your better bet. The 8hp, short lower unit OB on my 23 footer was overkill. Go lighter with the deeper lower unit, and you'll be happier, safer, and more maneuverable.

 

[HukilauMike]

I agree with those that suggest a 6 hp four stroke is big enough, and the longer shaft is definitely a big plus. The only caveat is the lack of electric start on that motor. If you are used to a pull start motor, then I think its a no-brainer: 6 hp extra long shaft is way to go.

 

[Winkfish]

Loving fishing and therefore having a fishing boat, I belong to a fishing forum (with a lot dedicated to outboards). The one piece of advice that's ALWAYS given to someone deciding on a motor for a given boat is to go with more power. You may just need that extra power one day, especially with a sailboat.

A 4-stroke is no more powerful than the same HP 2-stroke. 9 hp is 9hp whether it's a 2 or 4 stroke. They just operate differently.

You can get outboards with different shaft lengths and different props, so you can customize to your needs.

Will you be leaving the outboard on your sailboat or taking it on and off? Thinking of the weight issue.

Are you stuck on Tohatsu? Other manufacturers may have something in between like you seem to be looking for.

I'd still say go for the extra power if possible.

 

[wonkodsane]

The one piece of advice that's ALWAYS given to someone deciding on a motor for a given boat is to go with more power. You may just need that extra power one day, especially with a sailboat.

On a planing hull that might be good advice.

Why cost yourself more in fuel due to engine displacement, # of cylinders, and climbing your own bow wave at hull speed when you can get something designed specifically for sailboats which will give you better control and economy?

 

[RichH]

I agree with winkfish.
With a 9.9hp you will have that power IN RESERVE when in storm etc. conditions where a 6 Hp will be 'straining' very hard to push such a boat through heavy chop and high winds.

I dont know where Valetta is; but, outside the USA or other places with extreme environmental over-regulations and restrictions for myself I'd seek out a Yamaha 2 cycle, 10Hp - extremely reliable, robust, more HP at less weight, 'bombproof', less complicated, worldwide availability for parts, etc. ... and the Number 1 reason: the carburetor wont be as sensitive to ethanolated gasoline/petrol.
Tohatsu Outboard engines are EXTREMELY sensitive to degrading gasoline/petrol .... and you must ALWAYS use FRESH gasoline in them or you WILL have carburetor problems.

 

[hman]

I cast my vote for the lighter engine with the longer shaft too......The extra horsepower won't do you any good if the prop keeps coming out of the water....

I downsized from a 9hp to a 2.5 Honda 4 stroke with the long shaft several years ago. It pushes my 23 at hull speed and although it's slower in a current, I can still make headway, especially if motor sailing.

 

[Winkfish]

First of all, it is because a sailboat hull is not a planing hull you would want more power. It's much harder to push a displacement hull (steadily) through the water than a planing hull.

Second of all, outboards aren't "designed" for sailboats. They have long shafts and short shafts, and different prop pitches, all of which you can get on just about any outboard model. Now some smart marketers may have realized that sailboaters need the long shaft models, so they marketed them as "sailboat" outboards. But again, all these are options you can get on just about any motor.

In normal (easy) conditions, you'll probably be fine with the smaller one, but I guarantee that if you're in a strong wind or current, maybe trying to pull into a narrow slip, or in a crowd of boats, you'll want the extra power. One other thing, a more powerful motor running at half speed will be more efficient than running a smaller motor at full speed.

(Just a quick note: I am a sailor, too. Lost our sailboat in H. Katrina. Have the Boston Whaler for fishing.)

 

[hman]

I agree with your first point about planing and non planing hulls, but disagree with your point because more power will not push a non planing hull any faster. Torque via thrust then becomes the difference in a situation with current and wind adversely effecting the forward motion of the boat. As long as the prop can provide the thrust needed to keep the boat going forward, the horsepower doesn't matter.

Whether or not outboards are designed for sailboats really isn't a factor. They are made for boats of which a sailboat is a type. People have been using outboards on sailboats for over half a century now.....(I've had one on my sailboats for over 30 years) Manufacturers do take into consideration what is needed to push a non planing hull with their products, and design "sailboat" models for that purpose.

Last but not least, weight is a factor on a sailboat. More horsepower in the engine relates directly to more weight on the stern. That same weight is a factor in raising and lowering the motor in and out of the water as well as having to pull that starter rope and get it going...

You are right, in an extreme emergency situation, the extra horsepower would be nice to have, but the real question is, if you have enough thrust and power to keep the boat stable and going in the right direction at full throttle with the smaller motor, as opposed to half throttle with the bigger one, do you really need the "reserve" with all of it's drawbacks? We can agree to disagree, but my answer is "no". or, if the conditions are that bad, don't go out....wait for a better day.

 

[Rick Webb]

More Than 6HP is Not Needed

I tried a 9.9 on my boat and other than the additional weight I noticed no difference than with my 6.0.

The eight would be tempting just for the smoothness the other cylinder gives the motor.

I have a 25" 6HP two stroke Mercury which for it's model year is a two cylinder motor. If you can get the extralong 25" motor it would be better but the 20" 6HP motor would be perfectly fine.

 

[Winkfish]

Hman, I can't dispute your first point because I'm not the engineering type. I was thinking more of cross-winds and currents, and swinging bows and such, where turning (or not turning) would be more of an issue. I agree with everything else you say, and it really all boils down to the uses and in what conditions the motor will generally be used and what you conditions you might be caught in unexpectedly, hence my questions in my first post. If the 6hp will do the job, that's that.

 

[hman]

No problem! Just my thoughts and opinions based on my own experience.....

 

[Nicky17000]

Hi Everyone,
I appreciate all the replies and basically everyone is right. It's more a matter of perspective. Another important factor is the type of propeller used. Sometimes a change in propeller makes a huge diifference even with the same motor.
Tohatsu was my first choice because here, they have a good reputation and the dealer is the nearest one to us. Actually I found him a bit snobbish and sort of pushed me off.
(he also stocks Mercury and Suzuki but they are more expensive)
I also checked Yamaha and Selva(Selva being rebadged Yamaha)
Probably I choose their 8hp with dual thrust propeller.

 

[tommays]

I had to rescue Seafever out of NYC and at 29' and 8000# the 4HP with the HT prop pushed it at 4.5 knots through all the ship traffic 16 miles to the boatyard

I also use the motor on my J24 and it has pushed the boat through 40 knot storms without issue


The only + would be less vibration a two cylinder motor it will not move the boat any faster

 

[BobM]

Malta?

You aren't emailing from Malta are you? My Wife and I visited a few years ago and stayed on Gozo.

 

[Nicky17000]

Re: Malta?

Yes Bob, I live in Malta.