Outboard Discussions

[French]

Well I went down to the boat last night to check things out.
I have a 6hp Merc Twin. The handle will not mount vertical and when placed horz. the lazarette have been slot-cut so it would fit. Perhaps some of the other outboards have a different handle position. I was told by an old sailor at one time , when I first got the boat, I could make do with a smaller HP motor about 3-4 hp. I think that would be way under powered. I guess it is time to do some research into outboard designs and power. The Nissan/Yammha 5 hp sounds interesting.
Any other suggestions?

My Merc runs well, and does fit,... however I would like something that will give me more manevirablity, even a little lighter would be nice.

[Bill]

Check out the boats at the Hoppe gathering on April 13. Most have ob's with control handles that swivel to the vertical. An 8hp Yamaha/Nissan/Merc 2-cycle should be a good choice. I have a 5hp Merc (very light) and it works fine in most conditions on the SF Bay. Fighting an ebb at the GG, however, is another matter The cost difference, as I recall, is about 1/3 less compared with the the 8hp 2-cycle.

[commanderpete]

French

If your Merc is worth keeping, you can get a remote outboard engine control box. The throttle arm is removed and cables run to the shift and throttle mechanism on the outboard. The box is mounted in the cockpit.

You can see an example of one type of box on eBay Motors Item # 1815838190.

I have a Yamaha brand for my outboard.

[French]

Hmm thats a cool idea, I'll take a look

thx

[Mike Goodwin]

You guys running the 4 stroke outboards, have you replaced the prop or you still using the one that came with it ?
You should be using one with less pitch 7" , the one supplied is 8" , makes a big differance , lets you get up to RPM faster and less slip . 8" pitch is for planing dinghies and jon boats , some mechanics even suggest 6" or 6.5" pitch .
A prop shop can re-pitch it for you for a few bucks ( cheaper than a new prop ).

Mike G

[Theis]

Returning to the original issue of lower unit corrosion, I just found out yesterday that lower unit corrosion, and more importantly prop corrosion are almost inevitable, even in fresh water, and even with the zinc scrifical corrosion plate.

It even happens with stainless steel props, unless they have a high concentration of nickel.

The only way I was told to resist corrosion is to keep the prop/lower unit painted. In the case of the prop, the paint comes off the edges, the electrolysis starts and is seen even in the center of the blades where the paint is bubbling/blisering off.

Ah, the elements have a way to beat the best that man can muster

[Mike Goodwin]

We picked up a matched pair of new Nissan 6hp 4 strokes for Ariel #45 and Commander #105 .
Will run them side by side with various props to determine best pitch to push boat .
55lbs of sweet quiet nearly clean propulsion.

[D. Fox]

I'll be very interested in the outcome. I have the 5hp Nissan 4 stroke (love it - as you said, clean and quiet) and still have the original prop. Thanks,

Dan

[Mike Goodwin]

Mercury ,Nissan & Tohatsu ( same motor, all made by Tohatsu ) recommend a 8x7 prop on the 6 ,5 & 4hp for displacement hulls ( the 4 comes with it ) the 6 & 5 come with a 'square prop' 8x8 ( actually 7.9x7.9 ).
My mechanic , from his experience , say to skip the 7 and drop to a 6 or 6.5 pitch . He's a licensed Nissan service center and seems to know what's up .
I'm going to buy a 8x7 try it and log with the GPS what it does then have it re-pitched to 8x6 and see what that does .
The following is over-simplified and not scientific;
at 4000 rpm the 8x8 prop is trying to go somewhere between 20 and 30 knots . Not going to happen on an Ariel .
At 4000 rpm the 8x6 prop is trying to go somewhere between 12 and 20 knots .
now you have slip and losses that can be 50% which brings you down to 6knots which is close to hull speed .
All that wasted revolutions on the 8x8 is like spinning the tires on a car , not getting you anywhere fast , the 8x6 is like switching to a fatter tire with more tread ,or a lower gear, that delivers all the bite to the road and propels you forward & stops you when you engage reverse.
The only drawback about downpitching ;
If you use the same motor on a dink or skiff that planes , it wont go as fast because you have shifted to a lower gear .
It only takes 5 minutes to switch props so buy a spare and have it pitched lower .

Mike G

[scottwilliams]

I PURCHASED THIS MOTOR AND AM CURRENTLY USING IT ON MY SAN JAUN 21 WHICH I HAVE RECENTLY RESTORED - IS THIS ENOUGH MOTOR FOR THE ARIEL . ? THANKS- SCOTT

[commanderpete]

This calculator says that you need 7.8 h.p. to push the boat at hull speed.

http://www.geocities.com/jvandrey/fl...alculator.html

But, hell, a Honda 4 stroke is a nice engine. Give it a whirl. It will get you in and out.

But, you won't make much progress against a chop or strong current.

I get currents of about 2.5 knots. Can be slow going, even with an 8 h.p.

If you get a new engine, be sure to get a long shaft.

[D. Fox]

I use a 5hp Nissan longshaft on my Bristol 27. I've been very happy with it. Its given me good power motoring into 20kt headwinds. The only time I found it lacking was motoring straight into steady 35kt winds, gusting to 45kts, with 2-3 ft waves. Couldn't get more than a couple kts in those conditions. My boat displaces 6600#, and I get 5 kts at 1/2 power in calm conditions. I went with the smaller motor to keep weight down in the stern - B27s (and Ariels I think) tend to squat with too much weight back there. There was a thread on this a couple months ago you may want to look at. Suggest you mount the motor and try it out for the remainder of the season and see if it meets your needs.

Dan

[MarkCreeker]

I am the new owner of a Commander, hull 202. She's complete except for the motor, and I will be purchasing an outboard shortly. I've read the advice posted on this board regarding outboards, and I still have some questions. I'm hoping that someone out there is still willing to flog this possibly dead horse.

1. 2-stroke vs. 4-stroke. Outside of California we still have a choice. I've heard that the newest 2-strokes are no less environmentally friendly than 4-strokes. I'd prefer to get the 2-stroke because of size and weight issues, as well as ease of maintenance. A 6 hp 4-stroke looks like the biggest that would fit in the well, and weighs about 55 lb. An 8 or 9.8 hp 2-stroke looks a little bigger, and weighs 60 lb.

2. Power/hp minimum. There seems to be general consensus that 6 hp is adequate to push an Ariel/Commander. I will be sailing in the Long Island Sound, and there's not a lot of chop. I'm more concerned with flukey winds and getting myself back home, and I think I'd be safe with 6 hp.

3. Is more better? My question now is whether it's worth investing a few more dollars for more power. Actually, the basic 8 hp 2-stroke costs the same or less than the 6 hp 4-stroke. So, given almost equal weight and cost, is there a compelling argument for the 6 hp 4 stroke vs the 8 hp 2 stroke? Hell, for that matter, why not the 9.8 hp (except for the $'s!)?

4. 12V Charging System. Is this feature worth the extra $'s?

Thanks in advance for any feedback.

Mark

[Bill]

Check the second or third post in the "Threads of Note" post at the top of the Tech forum. It deals with hp computations for the Ariel/Commander hull. An 8hp 2-cycle appears about ideal from a weaght to hp and hp to hull speed solution.

[Mike Goodwin]

I have both , a Nissan 6hp 4 stroke , a Johnson 5hp 2 stroke , and a Cruise & Carry 2 stroke .
The Nissan is brand new , the Johnson 3 years old and the C&C is ancient.
The 2 stroke will use twice as much gas or more and at low RPM's discharge unburned oil into the sea , 2 stroke fact of life . It is more powerful and louder for the same HP although lighter , nuther 2 stroke fact of life .
No mixing gas and oil for the 4 stroke , so if you top off a tank , you can forget the higher math and if you get it wrong on a 2 stroke , you foul the plug or burn the rings out . They are not inviornmentally friendly untill you get to the higher HP models with 'oil injection' .
All 2 strokes smell , I dont notice my Nissan .
Also I can talk to someone on the bow with the Nissan running hard , can't even hear myself with the Johnson .
I get 5knots in flat calm water with the wrong prop on the Nissan 6hp ( new prop will be here Friday ).
Which ever you get will need a 'power' prop of about 6" pitch , 9x9 is standard and wont give full power or rpm's , unless you buy a designated 'saildrive' , 'sailmaster' ,etc. which will have the right prop .
Yes to the alternator option , it aint much but will light the running lights or top off a battery that is low ( not enough for Airing's microwave ) .
Which do I prefer?
I like both , my wife only likes the Nissan and has very ugly things to say about the Cruise and Carry ( poor thing only weighs 12lbs and is asked to push over 5000lbs of boat).