Relatively quiet, less smokey 2-strokes

I've come to think that I need to abandon the 4-stroke outboard idea. Even the Honda classic 8 hp is notgoing to work. It doesn't come with a 25" shaft, or electric start and alternator.

So...back to the drawing board. Does anyone have suggestions on new 2 stroke engines? I have a 1993 Merc 9.9, but the 50/1 oil ratio is a mess. Does Yamaha, Nissan or Honda make a 2 stroke that anyone is using that fits the well without modification to the well or to the engine? Any other recommendations or comments?

Thanks for all the suggestions so far.

Bill

The Nissan 8hp 2 stroke is a honey of a motor and fits too, why you need a 25" shaft ?

The Merc 9.9 has one, and it never cavitates, even in steep hobbyhorse type conditions. So, I think it is better. I'd like to hear other opinions on that, but it seems that if you can get a 25 inch shaft, it would be more desirable.

Thanks, Mike, for the Nissan recommendation. I'll look into that one.

In an earlier thread on ob's, the consensus seemed to be that the long shaft ob was not likely to cavitate. We were discussing the 20" long shafts on 5-6-8 hp engines.

Did anyone have any comments on the 25" long shaft? I assumed that it was better, because that's what came with my boat. What would be the advantage of the 20" lower unit over the 25"? It just seems that if the prop is a little deeper it would cavitate less and would be able to provide more push in really adverse conditions.

I could see that the 20" would be lighter and easier to move into and out of the well, but ... If you were planning to really cruise this boat, not just daysail, wouldn't it be better to have the added power when you absolutely have to have it?

I have a friend who owns hull #1 which originally came with an inboard engine of some kind (atomic 4?) ... anyway, it was ruined when he bought the boat (the boat itself was nearly ruined) and now he's put in a 16 hp Yanmar diesel. I'd rather have a diesel no doubt. I know that the outboard in the well is a compromise situation no matter what, but as long as I am going to replace the outboard, I want to get as much potential out of it as I can.

Click on the "search" button at the top of the page and enter ob, outboard, or similar search word. You should get all the ob posts. Try refining with "length" or "20 inches" or "long shaft."

As Bill says, the various posts to this technical forum related to OB motors really are helpful. They influnced me to purchase a Nissan 6 hp four stroke motor.

The points you raise are valid, but power and shaft length come with heavier motors and generally ones that won't lie down in the lazarette for storage. My Nissan 6 long shaft barely fits horizontally in the lazarette. I do not imagine that the extra long shaft motors will store in the lazarette. So you might want to add motor weight, and ease of storage to your criteria.

Man, a Yanmar 16 hp in an Ariel. That certainly would be plenty of power, but hull speed is hull speed. Still, when bucking a tidal current or serious swell, the extra power would be great.

Scott, How do you like the Nissan 4 stroke? What are its weaknesses, if any, in your opinion? I haven't removed the engine that came with Haabet because it weighs 85 pounds and is hard to get into and out of the well. That's one of the reasons I bought the Garhauer lifting davit. But if I did, I had planned to put it into the port cockpit locker on a bracket. So the issue of being able to lay it in the lazarette isn't so important to me.

Now that I've read the various posts on 2 and 4 stroke engines that I was directed to, I'm leaning toward trying to get the engine I have to work properly. I think it needs a fuel pump rebuild. It won't develop full power, but bogs down when you put a demand on it. If that is unsatisfactory, I think I'll go with a 2-stroke, 8 hp Yamaha or Nissan with a 25 inch shaft and an alternator. I have a 6 HP Yamaha with a 25" shaft that I'm going to try out while the 9.9 Merc is checked out. It has the same power head as the 8 but the 8 is carburated differently to give it the extra power. My Yamaha doesn't have an alternator, so it is only a substitute until I check out the Mercury.

I must say that I have felt that ever since I bought this boat 15 months ago, I wondered how the Yamaha 6, which develops a lot of power for its nominal 6 hp, would stack up against the Mercury 9.9...power wise and smoke wise. The 100 / 1 mix should make it a lot less objectionable. And it always was a heavily torqued engine that pushed my last (smaller) boat against any tide or wind that I managed to get my self pitted against, rather than working with!

So ... is the Nissan 6 hp, 4 stroke smoke free, and powerful enough, in your estimation?

Bill

As you said, there is a hull speed limit, but power when you need it to buck a tide or headwind, or both, is what I hope to maximize, using the outboard option. I looked into the possibility of retrofitting a diesel, but it just doesn't add up economically. Haabet will remain as she is, with some sort of auxilliary outboard power.

You might want to measure the power head of the outboard, before you plan to stow it in the cockpit locker. It most likely wont fit, the head is too wide on every outboard I measured above 6hp.

I only have 24 hours on my new Nissan 4 stroke motor, and I have not yet switched to my second prop with a flatter pitch. So I am not the best person to ask. I bought the Nissan 6 based upon testimonials gleaned from this forum after looking at a range of options. The power appears to be fine for my kind of use. No rivers or tidal currents to speak of here, and I primarily use the motor to get into and out of the harbor. There is no smoke, and it appears to work just fine with the lazarette lid closed, although I usually leave it open to gain access to the handle while maneuvering in the harbor. As far as what I have read on this forum, the standard long shaft is long enough to prevent cavitation for most folks. An extra long shaft would be nice on any motor, but isn't necessary for my use.

Also, since we have a lot of floating kelp in these parts, any extra inches on the shaft just increases the chance of fouling the prop. I can more or less reach between the well and the motor and free the prop, although I once had to pull my Honda 7.5 motor at sea when this happened because of the volume of kelp wrapped around the prop.

I probably could have reversed the prop and spun the kelp away, but I opted to lift the 80 lb motor with my davit and free the kelp out of water. I had to cut the kelp away with my knife. It was wound that tight. Of course using the lifting davit at sea put both me and the davit in the way of a boom in the event of an accidental jibe. Fortunately, I had my trusted ninety-year-old helmsman with me that day and all went well. I do trust the guy. He once stopped a Navy Locomotive from going into the Honolulu harbor after a mechanical failure sent the train freewheeling toward a near-certain launch into the briny blue.

I do have two gripes with the Nissan motor, however. The flushing set-up could be easier, and the wing nut that increases the tension on the shaft so that the motor doesn't turn so easily cannot be tightened on my motor sufficiently to lock it in place. Indeed, the Nissan manual cautions the operator not to try to use the tensioning nut to lock the motor in place, for it was not designed to do that…or so says the manual.

So, as I am running about on my foredeck reattaching my lower shrouds after a tabernacle operation, and raising the main etc., the motor slowly changes course, which makes the process of a single-handed escape from my harbor more difficult, and particularly so as I wander on my zigzag course though weekend harbor traffic. Not a fatal flaw so long as you keep checking on it, but a nuisance nonetheless. Perhaps I have been too timid in tightening that wing nut, because I have been told by a Nissan dealer that she has no problem using the wing nut on her personal Nissan to lock the shaft in place. I tighten mine as far as I can by hand (no wrench), and the motor still wanders off as torque does its thing.

As far as storing a motor in the cockpit locker, I have a hard time fitting a bucket through the hatch of my cockpit lockers, and I have to crawl in sideways myself, so I am in agreement with Mike. Do some measuring before you try to drop a motor into one of those lockers.

The lazarette locker is a dandy place to store my Nissan 6 four stroke long shaft motor and was a dandy place to store the Honda 7.5 long shaft motor before it. The other advantage of the lazarette is that, unlike the cockpit lockers, it is ventilates below (the well), forward (the hatch behind the tiller), and above, the two vents in the top hatch. Also there is absolutely no lifting by hand. The Garhauer lift lifts my motor from a horizontal position in the locker to vertical and drops it into the well. I am not so sure how well the davit would work if you tried to use it to lay the motor down in one of the cockpit lockers. You might or might not have to do some lifting sans davit, since if it fits in the cockpit locker at all, the motor head will probably only fit head forward where the locker is wider.

When you install the Garhauer lifting davit, follow Gene Robert's written instructions for the Myron Spaulding designed installation used in Gene's boat. But crawl into your cockpit locker first and check out the floor under your cockpit. At least on my boat, hull #330, the floor is made up of multiple layers of glass with spaced longitudinal strips of encapsulated wood strips (boards) running fore and aft and is not a solid plywood core, so where you drill the holes for the base mounting bracket for the davit may be very important. Outside of specifically where to drill the holes, the installation is a snap. Gene's instructions are in the Ariel Manual available from the Association. I used teak backing plates for the base below the cockpit floor and for the ring attachment bolts inside the cockpit locker. And have fun working behind that vertical cockpit support post where you mounting base bolts will penetrate the cockpit floor. If you drop a nut, you will probably have to shove it with a flexible rod down into the lower bilge where you can retrieve it in the sump behind the battery.

Of course you are not supposed to drop things, but suffice it to say that two one inch square lengths of teak duct-taped together so that the duct tape formed a flexible joint did the trick for the nuts that I dropped. Using teak is not necessary. Any wood will do. The harbor board is considering selling steel mining rights in my slip for what I have dropped over the side in the past two years.

Thanks Mike and Scott...

And the Ariel Association...

I love this forum. I really appreciate your input.


Bill

To all those who lift and flush their engines after each use, I salute you. Too much work for me.

I've got a Yamaha 8 hp. Its 10 years old and still going strong. I leave it sitting in salt water 8 months a year. Almost no corrosion. Yamahas are supposed to be particulary good that way.

I've never fresh water flushed it.

Its got a charger and electric start. I pull-start it most of the time anyway. I don't know why.

There was only one time she wouldn't start. I couldn't figure out what was wrong. I kept pulling the cord ....vroompa....vroompa....vroompa.....no dice. Damn near seperated my shoulder trying. I was getting seriously depressed. Then I noticed the kill switch lanyard clip had come out. Clipped it back in and she started right up.

God, I love that little engine. Her name is "Yoshi, The One Pull Wonder."

If she ever dies, I'm getting another one.

Pete,

Do you have to run your boat with the laz open? As I said, I have the same engine, but the 6 hp model (1989), which is a big 6, with the same block as the 8. It has a 25" shaft also.

I'm encouraged to hear that the 8 has an alternator and electric start. I need those features, although I agree with you that the Yamaha motors are excellent. One pull almost always does it, so the electric start is not as critical as the alternator.

What is the smoke situation on your boat? Do you have any special exhaust arrangements to allow you to close the lazarette?

Bill

Not much smoke. I have remote engine controls so I always run the engine with the laz hatch closed. Never choked.

I have a friend with a 1964 Rhodes Seafarer. (Dutch built, before they started building crappy models in the U.S.) Similar size boat that also has a motor well. He's got a Yamaha 6 hp. Always keeps the hatch shut. No problem. Seems to drive the boat fine.

He doesn't pull or flush it during the season either. We don't have shore power where our boats are kept, so this may help avoiding corrosion.

Maybe the water is saltier here :) Not flushing the engine almost put me on the rocks when the engine would start, but not continure to run. A fortuitous tide change got us away from the shore and we were able to sail into the slip.

Examining the engine, I fund that the water pump was clogged solidly with salt! The engine was not getting any cooling and it would freeze up after a couple of minutes of use. Cool down, start again, stop. Repeat.

We flush now after EVERY use, because we remove the engine from the water after every use. From Peter's experience, I would have to assume that leaving the engine in the water all season prevents salt buildup. My guess is that this is probably because there is no evaporation occuring and therefore no chance for a salt residue to form.

I am still using my 1987 Johnson 9.9... And it stays in the water all season long. One of the things that keep it going is that I have my motor guy drop the lower unit every year. He cleans it out and checks the water pump at the same time. Every 2 or 3 years he will replace the impeller. I have had other problems, but they stem from having a 15 year old motor.

I have had the power head rebuilt at one point and this past year he rebuilt the megaphone/ exhaust header as that was rotten.

So I chug along with my 9.9 longshaft and try to figure out what I am going to do when really dies. And every year he says that I have another couple of years left in the motor.

John G.
Valhalla
Commander No 284