Outboard Motor Size

[Stef]

I'm thinking of upgrading from my 1978 7.5 Merc. to a newer 4 stroke. What seems to be the motor of choice? High thrust prop? How light can I go?

[Tom Elsen]

Hey Stef
It really depends on the water you sail.
We use a Nissan 5 (four stroke). 46 lbs or so. Love it. It's great for most inland lakes. I think I'd want something a little bigger in waves and/or strong crosswind docking maneuvers.

[Mark Gutteridge]

Stef;
On Hunting Party we use a Nissan 6 HP 4 stroke.It weighs appox 53 lbs.
It has lots of power ,uses very little fuel and has been very dependable.
I believe the class minimum is 4HP.Someone will correct me if I am wrong.
The nissan as with all 4 srtokes has to be stored properly or the oil will drain out.Also if it is stored with the power head in a downward position some oil will get into the cylinder and mess with the combustion computer.
Chimo;
Guts.

[LarryE-old]

I have a Tohatsu 6, 4 stroke. Bought it almost 3 years ago and its used almost every week, year round, in salt water.
Can't say anything bad about it, real important to store it on its handle.
I got the extra long shaft, for the same price of a long shaft, as thats the one they had in stock. The prop stays in the water, even in large waves, motors really sweet.

[fleck]

Stef,

The nissan, tohatsu, and Mercury , 4,5,and 6 Hp are almost exactly the same engines. Each is a 123 cc engine. The differance is in the carb. These engines with a power prop are really impressive. Almost all outboard engines are propped for a speed that is greater than you will use on any sailboat. They're build mostly for planning hull boats and dingies. The power prop is build to create max thrust at the speeds that the sailboat will use. It also has a much greater bite in reverse.

Anything more than the 6HP 4-stroke is, in my opinion, overkill. The extra long shaft would be the best. Especially for the waves that can roll into the PA side of Lake Erie.

Below is the text from an old post on the same subject (if you don't have it already):

I'd bet that the 4hp would meet any speed requirements. If not, here's even better news. The Merc/Tohatsu 4hp, 5hp and 6hp all are the same size motors (123cc). I'm pretty sure the jets in the carb are the only difference. I'm using the 5hp ( I wanted the external tank) with the 'power' prop and it works great, hull speed or better. Be sure the keep the mount as low as possible, the 'extra' long shaft would be nice. The power prop has a lower pitch and flatter blades. With it we were able to TOW an S2 10.3 doing 4-4.25 knots(flat water). Mercury part number is: 812951A 1 .

[LarryE-old]

I can back up what Fleck said about the power prop. After reading his post I ordered that exact part #, my original one had a slight bend.
Nice gain of low end power.

[Stef]

Thanks guys.
Yesterday I did notice that the Tohatsu/Nissan 4, 5 & 6 were all the same weight. Power prop sounds like the best idea. I never had my 7.5 merc wide open, maybe half throttle. So, it's a waste of HP.
I have 5 months to find a good deal on the 6 HP.

[Pete]

The Tohatsu is made by Nissan. I believe they're exactly the same.

[grandillusion]

there is an outboard motor store on ebay there like $1450 with free shipping outboardsonline, I want a new one and the tohatsu[nissan 6 is my choice but the evinrude 8 is still running great, less for the 2 stroke smoke and it uses a ton of gas

[Bob Kirsten]

Guys, We sail Lake Erie and Lk St Clair, and in big waves there is no beating a 10HP Honda 4. I had a good running 5HP 4 stroke on my J24 which was good most of the time, except in bigger waves and wind over 20Kn. I have never run with the prop you mention, which does sound interesting, and it might change a lot for the lower HP motors.

Bob Kirsten
DD Mau
@438

[Stef]

Seems like there is more than 1 high thrust prop. available. They offer 3 sizes, 6", 7" and a 6" "elephant ear" prop, the later being considered the true high thrust.

[Stef]

Got a motor.
6HP Tohatsu 4 stroke(Tohatsu makes Nissan & Merc). Ultra long shaft (25"), with high thrust prop and as a bonus it has a charging system factory installed, all for $125 more over standard. Free shipping and NO TAX except TN residents. Outboardsonline had the best deals, thanks Grandillusion.
The 4,5, & 6HP are all the same motor weighing 55LBS, different jets in the carb.

[BarryE]

I switched a couple of years ago to the Tohatsu 6hp four stroke; I sail out of Port Huron, Mi about 1 mile south of Lake Huron on the St.Clair river, river current can be 5+ knots at times especially right under the Blue Water Bridges, especially if there is a strong north wind behind it. So far no problems, even with the stock prop.
Engine replaced a worn out 82 vintage Johnson 10hp, 2-stroke. New engine is tons lighter, and feels like it has more thrust especially down low. (these are my impressions, I can't quantify this). I'll probably spring for the better prop before launching in May.