Outboard Discussions

[Rico]

I have a 2003 NISSAN 6HP, 4-stroke outboard engine with the long shaft (20”) on the Mephisto Cat.

I’ve used this motor in San Francisco Bay, as well as on the recent coastal voyages from Ensenada, MX, to San Francisco as described in previous posts.

The typical issues faced with outboards on Ariels & Commanders seem to be the following:

1.- Will it fit in the outboard well?
The 6 HP Nissan fits quite nicely in the well being able to rotate pretty much throughout its full range. The lazarette cover closes, clearing the top of the motor by two to three inches.

The bottom unit is thin & slender reducing hydrodynamic resistance while sailing with the motor in the motor well – which I often do….

This motor only weighs 55lbs (Per Nissan) which makes it easier to handle. I think that this is the heaviest you can go while still being able to (relatively) easily handle an oddly shaped mass as an outboard motor.

2.- How much power do I need? (HP)?
I find that this motor moves the boat quite well. It will cruise at about 4 to 4.5 knots at ¾ throttle, and will reach hull-speed (~6kt) at a bit less than full throttle.

While sailing in SF bay in the past, where the winds and currents are not to be ignored, I have found the need to use the full power of this motor while fighting a strong current, or while motoring into a marina’s channel with a strong wind on the nose.

While using the motor during coastal cruising, I found that when faced with strong winds on the nose - and the resulting wind swell - the going gets slow. Mostly because out in the open, the wind swells easily kill your forward momentum.

In these cases a bit more horsepower might help, but these are unusual circumstances for these boats. AND I would argue that if you find yourself in this situation at that point you’d be MUCH better off sailing off with a reefed main and a storm headsail (or just the storm sail…) as this will improve your ride and likely progress as well, so the benefit of a bigger outboard in these cases may never be enjoyed… while you’d ALWAYS be burdened by the big outboard’s weight.

However, in my time spent in coastal marinas, such as Marina del Rey / Santa Monica Bay where currents are negligible, I found myself wishing for a little (maybe 2-3 HP at most) two stroke motor that I could pull out in a jiffy… This would be more than enough to get in and out of the marina when the winds were blowing. If I were still in this environment, I’d definitely go with the tiny motor.


3.- How fast will the boat go?
6HP will get you to hull speed. There is no need for more power. 20HP will maybe give you hull speed PLUS maybe 1 knot more, PLUS a big bow wave in front of your boat… while using MUCH MORE Fuel. In short, there is no need… (unless, as I described above, you will be ONLY sailing against very strong winds in sheltered waters -with no wind swell. These conditions would allow you to enjoy the extra horsepower to fight the wind, but these conditions are unlikely…)

4.- Shaft length
My motor has the 20” long shaft. (Note: For 2009, Nissan is offering a 25” extra-long shaft.)

I found that the 20” long shaft works really well on these boats. The steepest swells faced were while motor sailing around Point Conception where we saw 8-10 ft ocean swells that were far apart enough to not present a problem (11-14 seconds). Big swells are not a problem for the motor, but when these swells are reflected by the concave coast between Point Conception and Point Arguello, and become 4-5 ft swells coming in opposing directions, plus toss in a 1-2 ft wind swell… All of these combining at random can present a tall chop which can be a challenge.

Even in these conditions the prop managed to stay in the water but did suck in some surface air for an instant a couple of times as the conditions above combined to produce a steep/deep chop. Note that when the cavitation happened, it was quite unexpected based on the behavior of the boat at the time, and never due to a severe pitch or roll. It was simply a very steep chop resulting from the combined swells.

The cavitation was only for an instant causing the revs to increase, but only for an instant. I do not think that the motor had time to reach max revs. I do not think that this is an issue based on the amount of time that the motor had to work in these conditions.

The 25” shaft would provide a bit more of a margin against the above situation, but most of us would not be in this stuff as a matter of routine… (hopefully). The down side of this extra length would only be a small added weight and the 5 extra inches increasing the required storage space.

Thoughts?

[mbowman]

Hey Rico, I too have a Nissan, but I have the 9.8 model. Great motor for my Ariel. It fits my motor well very good...... well it may be a little tight. I just had a lot of work on mine. $320.00 worth! New impeller, water pump, spark plugs, foot oil,etc... and he also found the bolts that hold the bottom drive unit on had corroded so bad that they were barely hanging on. He said I was luck the foot didn't end up in the lake.... (the motor was in salt water for 3 years). He drilled out the corroded bolts.... added new ones.... replaced "O" rings, gaskets, etc. I can't wait till it gets above 30 degrees to hear it start up on the first pull! Well here's hoping anyway!
I know a smaller motor will probably be ok for the Ariel, but when I was down on the coast of Alabama, Florida, the tides were really strong especially in the months of Jan thru March. And the extra kick sure did help out in a few tight situations.

[c_amos]

Ok,

I have had my Tohatsu 6hp 4 stroke for a few months now. I hate to say it, but I like the Yamaha 6 hp 2 stroke better.

I know this is a departure from the consensus. I do like the fuel use of the Tohatsu better, but that is about it.

The Tohatsu has to come out of the water for anything more then a day or two. The zinc is really really small and erodes fast.

The Yamaha is a 2 stroke so it has more thrust. I tried the pricey 'thrust prop' for the Tohatsu... it did make it back better, but it dropped the 5.2knot WOT speed to 5.0

I know, I know, it IS a sailboat. There are times though when cruising that you want hull speed. The opening bridge that opens on the hour that is between you and the anchorage you want.

I don't think I need more HP, just a better way to get it to the water. My Yamaha did that.

I would like to try the Yamaha 6hp 4 stroke.. but I doubt it would fit in an Ariel well.

The Tohatsu that I bought was ~$1450 with the charging option, and I paid another ~$115 for the thrust prop. I am sorry this is not working out for me, but wanted to post to share for others consideration.

If anyone is looking for a well cared for Tohatsu 6 with the charging option let me know. Also, if anyone has sucessfully mounted a Yamaha 6/8 4 stroke in an A/C well I would like to know of it.

Finally if anyone comes across a Yamaha 6/8 2 stoke in good shape (20" shaft) I would apprecaite your letting me know.

Thanks,

[Westgate]

Craig:

I wonder how much of the performance difference you are experiencing is the result of the switch up from the 2 to the 4 stroker? 4 strokes are different beasts in my experience. They tend to have better low end "power" but suffer in the top end.

The 6/4 yammy does have a larger engine than the Tohatsu (197 cc vs 123 cc). Might produce more torque? Have you seen a yammy 6 in action?

I know exactly what you are talking about wrt racing for bridges. What you forgot to add is the tide is ALWAYS against you when it's going to be close.

[Bill]

. . . I would like to try the Yamaha 6hp 4 stroke.. but I doubt it would fit in an Ariel well . . . Also, if anyone has successfully mounted a Yamaha 6/8 4 stroke in an A/C well I would like to know of it.

:

As noted elsewhere in this thread, Tohatsu makes the Yamaha and Nissen 4 & 6 hp 4 stroke engines Going to an 8 hp 4 stroke requires major modification to the engine well in the lazarette. See Ebb's photo gallery thread for one such modification

[Westgate]

Bill:

Tohatsu does make Nissan and small block Mercury outboards but Yamaha is made by Yamaha.

Andrew

[c_amos]

:

As noted elsewhere in this thread, Tohatsu makes the Yamaha and Nissen 4 & 6 hp 4 stroke engines Going to an 8 hp 4 stroke requires major modification to the engine well in the lazarette. See Ebb's photo gallery thread for one such modification

FWIW,

The Tohatsu plant makes the Mercury, Nissan, and Tohatsu outboards. They are the EXACT same motors, right down to the paint. The Mercury dealers will try to convince you otherwise but there is no difference. (Other then the Mercury being much more $$$)

[Theis]

I have found the zinc Yamaha sacrificial anode will last a couple years in fresh water, less than that in salt water. In fresh water a magnesium anode should be used but Yamaha doesn't make them unfortunatelyso I have to be certain to keep the lower unide and propellor painted so the aluminum doesn't become the sacrificial anode. I only use TriOx bottom paint as it doesn't react with the aluminum andis slime/algae resistant.

[ebb]

Did not respond to Andrew Westgate's #187 post. Sorry!

I know my situation is unique. But 100 plus pound 8HP OBs are not out of the question.
And therefor are not readily removable from the well.
Although I think I've noticed that new (2010) Yamaha 4 X 8s have lost 20# and
now have the garden hose attachment conveniently under the hood.

Amazing!
In the OB world this is about as important an innovation as sliced bread!!!

I naturally have the older model that needs the rabbit ears and the motor to be running to flush.
[later EDIT: I believe the Yamaha is a 2002 model and has that garden hose fixture for flushing. NICE.]

Has anybody here noticed how the garden hose flush works?
Can this fitting be retroed to an older Yamaha?
Is there a kit available?


Assume that lighter two stroke 8HP models are now available that run a lot cleaner - equal to the California ordained four strokers.
I believe they are around 50 or 60 pounds.
I may have to find one of them (in Nevada?)
because well flooding IS a real problem.
Could probably man-handle a 2010 two-stroke in and out of the well.



I plan on installing a Garhauer lifting davit for the steroid Yamaha.
That means the motor could be lifted and flushed in a vertical position.
But that means messing with a strap contraption everytime.
Having to use this strap-thingy seems stupid to me, really.

Another invention for Yamaha to come up with are built-in lifting eyes that you
could hook or tie on to that would raise the motor in a balanced vertical position.
That would make it easy to mount the clamp.
Took a hundred years for the garden hose flush to appear..........

[Scott Galloway]

Ebb,

I have not looked at the current model Yahamas, but my Nissan 6 hp four stroke has been modified by inserting a fitting into the flushing port on the bottom of my Nissan, and then hose clamping the hose barb on that fitting onto a Yamaha garden hose flushing unit from a model that they made a few years back. They may still be using the same unit now.

The Yamaha device is just a piece of hose and a cool little bracket that attaches to the housing of a motor. the Bracket his a female threaded garden hose plug. It is permanently mounted to my Nissan motor housing. All I have to do is remove the line from my gas tank, lift my motor with my Garhauer Lifting Davit, and while the moor hangs there out of water, remove the Yamaha flushing hose from its bracket with my hand and again by hand attach the male end of the hose on that unit to female end of my dock hose. Then with the Nissan 6 running (as per the Nissan operations manual), I run the motor until I run the motor out of fuel thereby flushing the motor and draining the carburetor.

The built in lifting eyes would be handy. I use a Davis motor lift that must be removed to check the oil. Its a snap to remove and a pain to reattach when the motor is in the well.

[c_amos]

....Assume that lighter two stroke 8HP models are now available that run a lot cleaner - equal to the California ordained four strokers.
I believe they are around 50 or 60 pounds.
I may have to find one of them (in Nevada?).........

The 2-stroke Yamaha's are the same design that they have sold since the 80's. They used chrome rings, and a different needle after (96?) to get them to run on 100:1 mix (still no where near as clean as a 4 stroke).

I loved mine (it was a 100:1) and would probably ditch my new Tohatsu 4x6 for one. The problem is the only ones (if you can still find one) for sale in the US have been the short (15") shaft models favored for tender motors. I had a chance to buy one in the Abaco's and should have jumped on it.

Looks like they stopped even marketing the 15" model in the US now (it is no longer listed on the Yamaha USA site)... here is a link to it for the overseas market (same one they have sold for years).

[Orca]

My long shaft Tohatsu 6 worked pretty well but the zinc is so little that it was useless. After about two months on the mooring it was gone. This year I put bigger zinc by drilling through the captivation plate. At the end of the season I was bringing the boat over to the marina in a 30 knot wind when the motor failed (it kept running but raced as something went wrong with the prop or lower unit. It looks like the lower unit corroded through in a pinpoint hole. The bigger zinc method worked with my old outboard for 10 years so I'm not sure what happened. Looks like a $500 bill to buy a lower unit . . . not what I was expecting.

[c_amos]

My long shaft Tohatsu 6 worked pretty well but the zinc is so little that it was useless. After about two months on the mooring it was gone. This year I put bigger zinc by drilling through the captivation plate. At the end of the season I was bringing the boat over to the marina in a 30 knot wind when the motor failed (it kept running but raced as something went wrong with the prop or lower unit. It looks like the lower unit corroded through in a pinpoint hole. The bigger zinc method worked with my old outboard for 10 years so I'm not sure what happened. Looks like a $500 bill to buy a lower unit . . . not what I was expecting.

Wow!

I am sorry to hear this. Both for you, and for me! I sure hope you don't need a new lower unit, maybe it is just the pin?


I pull the motor out of the well now, but did not with the Yamaha (I sailed more days then i did not when I was in NC.)

The zinc issue is not for the daysailor, but for the cruiser (as I see it). When cruising, you are simply not likely to pull the motor each time you anchor.

Even if it were not difficult, it would not be advisable, sometimes things happen that you need the motor for on a 'dark and stormy night'.

My old Yamaha 6hp 2 stroke had a big zinc, and would be happy for 6 months in the water...

[ebb]

Thanks guys for the feedback.
(Craig, imagine importing a 8C two Stroke from Australia!!!! Only 55LBS!
I'd never guess they were illegal in Nevada.)


To stir the waters, so to speak,
and if you are interested, find the Whaler Continuous Wave site and see if you can find these threads:
New Montauk: Engine Flushing Procedure.
Earmuff vs Backflush
Silently Flush Your Outboard Engine.
This last thread is older but if you can pick it up talks about using earmuffs while the motor is on the boat and in the salt.
Inventor of the 'Backflusher' specific for sailboats also has a few posts'
The corrosion problem is the same for all even if these Continuous Wave guys have 90 and 150HP OBs. The discussion centers around whether earmuffs will work with a garden hose on and the motor running in the vertical position.

Here is a plausible drill:
Shut off motor.
Leave motor on boat.
Tilt motor up.
Install earmuffs.
Turn on water.
Tilt motor down.
Restart motor.
Run until peehole water is not salty.
Turn off water
Tilt motor and remove muffs..

This supposes that the fresh water source is under pressure.
And this is of some concern for the guys on the Whaler site.
These folks are slanted toward Mercs and Yammys, and there is no mention
of a 6 or 8HP OB.
( It looks like the Backflusher never made it to production. Typing 'backflusher' into google
gets you directly to the thread at ContinuousWave.)

[ebb]

Finally dawned on me to take a look at the outboards in the garage.
There's a Seagull Silver Century, a SeaCraft 6 that came with A338, and the 4X8 Yamaha.
The earmuffs would have to be used with the Seacraft - and that's what had stuck in my brain - because I do remember running water through it at the dock.

The 2002 Yamaha has the (sliced bread) hose fitting screwed into a bracket beneath the hood.
You unscrew it and attach the garden hose to the female fitting which is on a short hose attached to the motor
Naturally I've mislaid the manual, but the forums above mention that it's OK to run fresh water through the motor when it's tilted. You must however be careful with the hose pressure.

ContinuousWave guys think that it's better to run fresh water through a running motor. They think that will desalt the whole motor best. But another guy will say the the engineers who designed it know what they are doing and that passive cleaning with the garden hose fitting through a non-running motor is just as good.

I couldn't argue. Desalting the motor mounted in place on the boat - NOT REMOVING IT - is buttering the sliced bread imco.
If and when the motor comes off, then run it in a tub.


ZINCs

I thought it was common practice to ground the whole OB with a large zinc attached to the boat under water near the OB.
The wire would be brought up to an unpainted point under the case. With our OB well, the wire would come up from a bolt on the zinc conveniently through the well. Where it is attached to the motor we should discuss.

That might be the answer to rampant corrosion that the smaller sincs attached to the OB can't handle.
Aren't they specific to the spot they are attached to?
They obviously can't do the job the whole OB zinc is supposed to.

Can we get concensus here?
Think it's really important.