4stroke/2 stroke, big or small?

[Swg]

Got a problem and would welcome your views. I sail a Shrimper(essentially a big day boat with a cabin) off a fairly exposed swing mooring on the mouth of the Firth of Forth ie the North sea. There's lots of room so sailing off and onto the mooring is fine. Kids, fishing and the very rare windless potter along with occasional overnight and niggling self doubt make me feel I need an outboard. The shrimper has an inboard well and an adjacent large locker. In 3 yrs my new Mariner 4 stroke, 4hp has run for 5 hrs. It lives in the locker except overwinter when it's upright in the shed. It's very hit and miss and I no longer have confidence in it. It's too heavy to take to shore and flush regularly and I think it hates infrequent use. Should I buy another and hope this was just an unlucky motor, buy a 2.5 hp which is light enough to take off and flush or an older 2 stroke which is lighter and less fussy about how it's treated?

 

[Lakesailor]

What makes you think flushing has anything to do with reliability?
Any motor hates infrequent use. Fuel gums up the carb.
Just get into the habit of starting the motor when you get aboard and if you don't need it when you come to drop you mooring switch it off.
These motors,(and I use two of them regularly) seem to have their own requirements re: choke and throttle settings for starting. Don't know why, but there it is.

Other than that the most reliable motors I have ever used.

 

[VicS]

Got a problem and would welcome your views. I sail a Shrimper(essentially a big day boat with a cabin) off a fairly exposed swing mooring on the mouth of the Firth of Forth ie the North sea. There's lots of room so sailing off and onto the mooring is fine. Kids, fishing and the very rare windless potter along with occasional overnight and niggling self doubt make me feel I need an outboard. The shrimper has an inboard well and an adjacent large locker. In 3 yrs my new Mariner 4 stroke, 4hp has run for 5 hrs. It lives in the locker except overwinter when it's upright in the shed. It's very hit and miss and I no longer have confidence in it. It's too heavy to take to shore and flush regularly and I think it hates infrequent use. Should I buy another and hope this was just an unlucky motor, buy a 2.5 hp which is light enough to take off and flush or an older 2 stroke which is lighter and less fussy about how it's treated?

For a boat that size IMHO you need an outboard no smaller than 4hp. Preferably a little larger. I have a 6 hp Evinrude Yactwin on a 19 foot boat

Fettle up the Mariner and get it running properly. Use it more.

Remember that a 4 stroke may only be stored/ carried /laid down in certain positions .. See the owners manual. If you are not observing those restrictions it could explain the problems you are having.

 

[Swg]

Thanks both for taking time to respond. Yes I know how to stow and how this motor likes to be started. The issue to which you both refer is central I think ie it's a sailing boat on which I like to sail. Lugging the beast out of the locker to set it in the well each time I go out is a bit of a hassle. Lake sailor I wondered if lack of flushing was contributory. Do you flush out your ob's during the season? Ifine were only flushed once or twice would it matter ? Finally, the little anode is worn and ive got a new one £8 for something less than an inch square !however, the old one appears to be 'fused' around the housing. Any ideas ?

 

[Lakesailor]

I am a fresh water sailor so it doesn't matter to me. I flush every I run it!

The only problem with not flushing is the cooling water galleries may block up with the salt residue and corrosion products.
That will lead to overheating which will effect the running of the engine eventually, but certainly not the starting.

 

[Alltnaha]

I have had the same with an underused 5hp - lack of confidence in it being the worst bit.

So I have gone back to using a very old Yamaha Malta which is 3hp, 2 stroke.

Totally reliable , takes all sorts of mistreatment including old fuel . Also simple to service - I am not that mechanically minded but found it dead easy.

Light so I use it on the tender out to the mooring , and seems very powerful for its size/weight.

 

[VicS]

FWIW I flush my 6 HP Evinrude once a year ........ when i get it home again at the end of the season.
During the summer it remains on the lifting bracket but at least being nearly vertical it drains well.

I have had it for 27 years all but a few weeks.

But its not a rebadged Far-eastern built thing.

 

[lw395]

I would suggest learning to drain the carb, this will often sort poor starting, as the usual culprit is a drop of water in the jets.
Ideally learn to strip the carb and clean it, but this should be less necessary on a 4 stroke.
A new spark plug is never a bad idea, I would prefer an NGK in most cases. Carry a spare if possible.
Frequent use is good, eventually corrosion will get the better of any engine if it is not flushed though. Even occasional flushing will help remove salt build up. Many engines do ten years without any flushing at all, problems often only occur when dismantling is needed.

 

[ProDave]

Well just my 2 pence worth.

I have a Mariner 4HP 2 stroke.

On the two occasions I transported mine on it's side, then hung it on the back of the boat, it just didn't want to work straight away. Embarassing when you are launching from an exposed slipway and the motor won't go.

The third time (this year) when I launched from the same slipway, I had transported my motor upright, and it started and ran no bother.

People say it should be okay to transport and store an OB on it's side, but that's not my finding. As lakie says, all engines are individual.

Mine hangs on a bracket on the transom so it's easy to lift it clear of the water and leave it there. Even a 2 sroke 4HP IMHO is too heavy to be moving all the time.

I only flush mine with fresh water at the end of the season. Perhaps I'm storing up trouble not flusing it more regularly, but as I say I regard it as too heavy to heave off the transome and bring it home every trip. Perhaps a mid season flush might be a good idea.

Is there no way to fit a mechanism in the well to allow the motor to be raised clear of the water but remain in the well (probably with the lid removed)?

A lot of people seem to hate transom hung OB's but the sort of issues the OP is talking about suggests an OB in a well just has a different set of problems.

 

[Lakesailor]

People say it should be okay to transport and store an OB on it's side, but that's not my finding. As lakie says, all engines are individual.

Interesting. The Mariner 4hp on Feckless starts better (1 or 2 pulls) than the Tohatsu 5hp on my motor boat (3 or 4 pulls).
They are both left tilted with the prop clear of the water.
The difference is that the Mariner is in the straight ahead position before tilting and the Tohatsu is on full port lock (To make the control cables less tightly curled when tilted) and that means the motor is tilted about 50° to one side.

I wonder if that makes the difference in the starting?

I will experiment.

 

[rob2]

I'm not yet familiar with the foibles of 4t outboards but my Tohatsu 3.5 2T does like to sit upright for half an hour before use, thrives on fresh fuel and I notice the handbook advises to open the carb drain after every use! Needless to say, I often transgress and then starting can be a sweaty, tiring business - but once warmed up it is reliable.

Rob.