Is it enough?

[chris mac]

I have a 5 hp tohatsu(shorter leg) on a San Juan 7.7. I was quite surprise at how well it moves me through the water. PO told me only problem he had was when he stored it on its side for the winter.( wrong side) had to clean out the carb before it would start again.
But I am on lakes, I would want a longer leg if I was in any waves, otherwise it has more than enough power.

[Stu Jackson]

Originally Posted by SUSailor

OK thanks. That clears it up.

This is the one I was looking at. My old two stroke has a 20" shaft so I thought that it would be long enough on the new one.

Tohatsu 6hp Four-Stroke Outboard Model MFS6CSPROL

Would I be better off with a 25" instead?

I love the fact that it comes standard with the alternator. That will be great back up to my solar set up for keeping the batteries charged.

1 Just about everyone with an outboard hangin' off the back recommends the longest shaft you can get.

2 Going to Alaska next year on that boat? If so, get the bigger engine.

3 To confirm some stuff already discussed: I just reread a 2003 (! ) Practical Sailor article on outboards. The wrong prop will not push you properly. The wrong prop can make you end up running at way less than full throttle and end up gumming up your carb and plugs. The wrong prop can make you run at part throttle and offset the whole idea of an alternator inside the engine - those alternators are pretty wimpy at a MAX of 6A at WOT, some newer ones may be larger - check it out. The constant refrain I hear on this and many other boating forums I read regularly is that Honda carbs get gummed up very quickly, and the solution is painful - constant carb cleanings.


[Although ethanol is blamed, it may NOT be the villan...although seafoam and stabil are suggested, this article suggested that the right prop and running at a good rate is better than all the snake oil out there!]

Perhaps all this is due to the wrong props!!! Tohatsu has a good rep. The differences between them and Mercury, for example, are minor -same engines - but the features MAY be important to you: things like where the clutch is for changing gears; don't know whether or not differences include whether or not there is a freshwater hose connection to be able to avoid using a bucket or "ears" for cleaning the engine with freshwater.

Do some more homework.

Good luck.

[SUSailor]

Originally Posted by chris mac

I have a 5 hp tohatsu(shorter leg) on a San Juan 7.7. I was quite surprise at how well it moves me through the water. PO told me only problem he had was when he stored it on its side for the winter.( wrong side) had to clean out the carb before it would start again.
But I am on lakes, I would want a longer leg if I was in any waves, otherwise it has more than enough power.

I was looking at the 6hp Sail Pro for a couple of reasons. It looks like it comes with the high thrust prop which is preferable on sailboats from what I can determine. It also comes with the alternator (it would be nice to charge the batteries some while under power) that is an option on the smaller motors. My big concern is do I order it with the 20" or 25" shaft.
As I said I like the idea of getting the prop further down in the water (might be a real help in rough conditions) but I wonder if I will be able to get it out of the water completely when under sail.

[Stu Jackson]

Originally Posted by SUSailor

My big concern is do I order it with the 20" or 25" shaft.

As I said I like the idea of getting the prop further down in the water (might be a real help in rough conditions) but I wonder if I will be able to get it out of the water completely when under sail.

Understood. Get the dimensions of the engine, get a stick that is that long and check it out.

Also, since you have an existing engine bracket, assure yourself that it can handle any additional weight. Many times folks moving from 2 to 4 strokes are "surprised" by the extra weight.

Good luck.

[chris mac]

With my set up(only one I've dealt with) when I raise the ob my prop is just touching the water.Pretty minimal drag so I'm good with it. with a longer shaft I would have to play with my bracket. You can prob make it work between lifting and tilt but stu's idea is a good one. Be sure before you commit.
And the idea of an alternator is very appealing. If you are replacing it anyways, might as well multipurpose it.

[Shawn67]

Originally Posted by SUSailor

but I wonder if I will be able to get it out of the water completely when under sail.

As long as your mount has enough clearance from the transom to fully tilt the engine you should be fine. It tilts way up, not horizontal but fairly close.

Shawn

[Shawn67]

"Many times folks moving from 2 to 4 strokes are "surprised" by the extra weight."

In this case there probably wouldn't be too big of a difference going from what is likely a 2 cylinder 2 stroke to a single cylinder 4 stroke. When I changed from the Johnson 8hp to the 6hp Sailpro I think I actually lost a couple of pounds.

Shawn

[Shawn67]

Found the thread about the Tohatsu 6hp and prop testing.

Nissan / Tohatsu 6h 4 stroke - SailNet Community

Poor signal to noise in that thread but around page 6 the talk of the elephant ears prop starts up. Not till page 16 that the thread starter tried it.

In a nutshell with the 8" pitch prop the engine couldn't turn over 3800 RPM and would have been developing less that 4hp. With the non-elephant ears it did 4700 RPM and produced about 35% more measured thrust. With the elephant ears it would turn 5000rpm and the thread starter talked about how it really just grabbed onto the water better. Another claimed 4.5 knots in a 8000# boat with the 6hp and elephant ears prop.

Shawn

[Hudson Force]

Sometimes the introduction of new terminology can cause communication problems. Many of us are accustomed to defining props by number of blades, pitch and diameter. When this "elephant ear" term first appeared in this thread, the props with and without the "elephant ears" both had a 6" pitch; therfore, can we assume that these "elephant ears" are just a bigger diameter prop?

Help me out here,- are we just talking about basic prop diameter or is this a feature of prop blade surface area and not diameter?

[Shawn67]

I believe the elephant ear is slightly larger diameter (.375" I think) but also has a somewhat different blade design to also increase surface area.

https://www.tohatsu.us/index.php?mai...ucts_id=106184

Shawn


Sent from my iPhone using Cruisers Sailing Forum

[thomm225]

One of the most ridiculous things to me is seeing (and hearing) a sailboat being pushed along by a screaming outboard at max rpm. This is why I like that my engine uses the standard prop.

I normally run it at 1/3 throttle but will go higher if necessary. I can hit 5 knots and more with a sail up.

My boat weighs in at 6700 plus.

I've had no problem with the carburetor gumming up or plugs fouling etc. My engine is a 2011 Mercury 5 hp 4 stroke. (25")

[Shawn67]

"One of the most ridiculous things to me is seeing (and hearing) a sailboat being pushed along by a screaming outboard at max rpm. "

Not suggesting that that is the way to use the engine either. The difference is with a higher thrust prop the engine is capable of producing more power and more thrust, if needed. If the engine physically can't rev to max RPM, in gear, the engine is not producing all of its power or thrust. A lower pitch prop (higher thrust) means the engine can produce more power, more thrust and more boat speed. It is a win win.

With my Sailpro I used somewhere around 1/3 throttle as well and that was around 4-4.5 knots by engine alone. The Tohatsu also smooths out quite a bit when throttled up. Full throttle would have me at 6 knots assuming the bottom was clean.

Shawn

[thomm225]

Max it out!

One afternoon last fall I sailed really fast across the lower Chesapeake. The tide gradually increased and the wind died so I headed to a nearer anchorage. But a bit exposed. I'm thinking the forecast must be wrong.

In this video, I'm thinking the tide was 3-4 knots.

This video is pretty crappy and doesn't show that the pilings for the fishnets were actually moving a foot to either side of center. I'm between 2' and 35'. My boat draws 4'. In the deep, the tide is worse.

The Atlantic Ocean is maybe a 1/2 mile to my stern.

Later this same night, the winds increased to around 24 knots. I was anchored just up a bit. Not a good night for sleeping....

https://www.youtube.com/watch?v=q6sH...m-upload_owner

[Hudson Force]

Originally Posted by Shawn67

I believe the elephant ear is slightly larger diameter (.375" I think) but also has a somewhat different blade design to also increase surface area.
......................
Shawn ........

Thanks, Shawn. Starting from your link I found the two 6" pitch props were 7.9" diameter & 8.375" for the (elephant ear) and I'm sure the diameter increase would have proportional increased surface area. 'good to know,- Thanks again!