4 stroke vs 2 stroke questions

I have friends who are rebuilding a '62 Rhodes Meridian (a very similar vessel to the Ariel). Their plans will have them cruising long distance in another year or so. They are looking for a 2 stroke 6hp outboard to power her with.

Part of the reason is for simplicity and ease of getting work/parts done on the ubiquitous 2 stroke engine, should they venture to places where small 4 strokes are not yet common.

Another reason that they don't want a 4 stroke is because though you can lay the engine on its side in the lazarette when not in use, heeling under sail could still cause water from the cooling system to migrate into places it should not be.

These seem like a valid concerns in the 4 stroke vs 2 stroke question. The cooling water thing is what concerns me most here.

I understand the 4 stroke benefits (quiet, cleaner, more range). But that is for naught if after a lumpy day (or weeks) at sea the engine has to be torn a down and rebuilt in order to run. Water in the cylinder and head is a Bad Thing.

I'm wondering if anyone has some knowledge they'd care to impart regarding that question.

Also - Could a 4 stroke be hoisted on a Garhauer davit and run dry for a minute to purge the sytem, prior to being stowed away, in order to avoid the chance of this happening?

Or should we all move to "keyhole sterns" a la ebb? :D

Thanks for input and edjumikation you can give on this topic. :)

Something I always found annoying was adding the oil to the 2-stroke OB fuel as well.

I saw a davit setup for an outboard - on a Cape Dory 26 website I think - nice back saving setup. (Not nearly as well done as Ebb's though... ;) )

4 strokes can be stored on their side , I do it all the time with my Nissan. The cooling loop is closed to the combustion chamber. You always lay it with the throttle on the high side. It is the oil running up into the head you have to worry about , but then all you have to do is hang it in the vertical posistion for about 15 minutes and all is well. Worst case pull the plug and crank it to blow oil out the cylinder .

The Garhauer lifting davit will raise the engine far enough to run the engine out of the water. (See Manual appendix for installation details.) In my experience, however, most but not all of the water will evacuate.

In the early '80's, OMC changed the shaft bearing near the head of the engine from bronze to something else. Some boats in racing fleet on SF Bay suffered bearing failures because we were storing the engines in the lazarette (rather than below) as a courtesy to a female skipper who was not able to get her engine below. On one tack or another, the head of the engine will end up lower than the shaft. (The water pump is near the base of the shaft.) Maybe this is why you see outboards stored on the stern rails of cruising boats?

Bill, when you wrote: "In my experience, however, most but not all of the water will evacuate.", do you mean by itself with just the effects of gravity?

About the Garhauer davit: It looks like it would make removing and stowing of the outboard when underway easier and safer. Has anyone used it when actually underway on an ocean, with the boat pitching and rolling? Just interested in observations in regards to that. Thanks for the info, Bill. (And that was nice that the SF Fleet was so accomodating. :) )

Mike, come to think of it, you're right: I think oil in the cylinder/head is what my friends stated as the bigger concern. So, the problem is oil leaking up past where it is supposed to be. If that happened, when the engine is cranked, there is the possibility of blown shafts and seals, and with oil in the cylinder, non-cranking, I guess. A 2 stroke, not having an oil reservoir in the crankcase, wouldn't suffer the same problem/concerns. Ah-hah! ;) It's all becoming clearer...

Here's a shot of the label on the side of a Merc 4 stroke:

http://liquid-epiphany.com/images/ph...rc_storage.jpg

So Merc wants their engines stowed throttle-side down.

I'd guess the reasoning for one side being the preferred down-side would be due to the oil passages being located on one side of the engine? Heeling 20* or more seems like it would make oil flow into the head anyway. Has anyone had difficulty cranking, needed to pull a plug, or experienced other problems with the 4 strokes because of this kind of stowage? Or is it just a remote possibility?

(Yes, I had a diesel inboard, all this outboard stuff is new to me. :) Thanks!)

I called Tohatsu and spoke with a nice gentleman there. Laying their 4 strokes down gives 2 things to be concerned about: the engine oil, and water in the lower unit.

Engine oil leaking due to improper stowage or excessive heel when properly stowed will not cause any long-term effects, and it is unlikely if stowed properly for that to even happen. He stated that it would be almost impossible for the oil to drain upwards if the engine is laid on the proper side, even at extreme heeling angles. If it did somehow, 1 of 2 things would happen: the oil would run into the cylinder, or it would run out of the engine via the carb. He recommended checking oil level as a quick way to ascertain if leakage in either direction has occurred. He said that no damage would be caused simply from the oil going up into the powerhead.

He said the BAD thing about the lower unit getting raised above the powerhead is that cooling water could flow back into the engine through the exhaust valves ($ound$ ex$pen$ive, doe$n't it?). He said that holding the engine in a vertical position (once out of the water) for a bit would allow any water to drain. I asked if pulling the engine thru a couple times would help, he said no, it'll drain just fine due to gravity.

Now I wish I could see a technical drawing of the cooling system. :)

Good thread!

I always watch these 4-stroke threads with some intrepidation. We all know how bad 2-strokers are over all, yet, I just haven't heard what I want to hear about the 4-strokes. Can't seem to find a 6hp with electric start and charging system. The 8's start to get pretty heavy to be hurling about without banging things up-so there's a lifting davit. Then there's the oil issue and cooling water gurgling about. Add to that, 113 came with a nice set of Morse controls that can be adapted to just about any motor and I can see myself being just that lazy.

Maybe some of you captains that actually get to sail these wonders could give your opinions and experiences regarding leaving the outboard in while sailing, pulling it out in different chop, motoring for periods, etc., etc..

Who out there wants to stick with their 2-stroke?

Now that I've solved our head issue and CPete hasn't given us an update on his mast, this is a timely subject to cover.

My 6hp 4 stroke has a charging system , but no elec. start. I do however have a vertical pull cord , so I open the lazy-rat and just grab the handle and pull up and it starts ( usually on the 1st pull ) the vertical pull is an option on the Nissan engines , no more busted knuckles reaching through the access hole !

I like that! I think an electric start would be whole lot easier to retrofit and add than a charging system.

How about sailing with your motor draggin'? Do you do that, or do you lift it out all of the time?

Leaving the engine in the well while sailing is like dragging a good sized anchor. But, if you're not in a hurry, that's probably ok.

The second drag (pun intended) is all the water you will scoop up through the well. The manual has a couple of possible solutions. If you are healed over on a stiff beat, the water really gets moving back there.

Why worry? On the one hand, if you always sail in fresh water, I guess it's just the nuisance of things floating around in the lazarette, etc. On the other hand, if you sail in salt water, then all that salt water is getting into the bottom side of the engine's head, the throttle, and etc. Someday, all that nice aluminum stuff begins to turn to white dust while the ferrous stuff just rusts. :mad:

Ever hear of people who have rigged their inboards to generate DC from a freewheeling prop? I guess there's no chance of doing that with an outboard. :D Plus, like Bill points out, why drag around an anchor?

But it brought to mind another topic - I got an email from a fellow the other day who has designed and built a wind generator for about US$30. He used a lawnmower starter motor and a 3-bladed R/C Helicopter blade. Says it produces 2 amps in 5 kts of wind, and 5 amps in 20 knots. I'll be looking into that idea a bit more. Sounds almost too good to be true, but is cheap enough to try. If the thing only puts out 2 amps, that's as much as the outboard charging systems I've read about, and there is no gas expense or motor noise involved (and wind doesn't set every evening, either :) ).

If I am sailing for less than 2 hours I sometimes leave the motor in the well.
Curious thing, Commander #105 scoops water like crazy , Ariel #45 barely scoops any.

Most people probably leave the engine in the water.

I very rarely pull it out. Can't be bothered. I'm lazy.

I try to go sailing two or three times a week. Often its a spur of the moment decision. I just want to jump on the boat and go. When I get back, I want to jump off the boat and go. Don't even scrub the boat down very often.

If I had to deal with pulling or flushing the engine I might not go sailing as much.

I'm not happy with the engine drag and keeping the lower unit in the water all the time, but I can live with it. I have a 1992 Yamaha 8hp two stroke in salt water. Once I had to replace the prop when the hub corroded away.

If the engine doen't last as long as it might otherwise, I'll just have to live with that too. I might think otherwise if the boat was in an electrically hot marina.

Around here, with an upwind slip you often can go sailing and never need put the engine in the water. In fact, Pathfinder leaves the ob on the dock when they are racing the Sunday Brunch series on the Oakland Estuary (a weight thing). Their marina is only about a half mile from the start.

Bill,

I get the impression that you are always racing when you sail. Do you go out for just a sail? And if you do, do you ever leave the motor in?

Tony G