New outboard advice

[Rob_Webb]

I am looking to buy a new outboard for my tender and my shortlist included the Mercury/Mariner/Tohatsu 3.3s, and the (cheaper) Johnson 3.5hp.

Because I had been advised that they were all essentially the same unit, I was wavering towards the M/M/Ts simply because they are darker in colour and probably easier to keep clean. But now I have been advised of two significant reasons to avoid them and to opt for the cheaper Johnson. The reasons given are as follows:

1. Apparently the cooling waterways on the smaller M/M/T units are very narrow and encourage eddies to form in them which cause deposits to build up and becoming 'cooked on' - this leads to restricted cooling flow which can cause sufficient overheating to damage the engine quite early in it's life - I was told only months in the worst cases. Apparently, if you religiously flush through with fresh water after every use it alleviates the problem but not if you are a more casual user with infrequent access to a f/w tank.

2. The props on the M/M/T use brass drive pins which shear very easily if you shift into gear at anything above idle or lightly touch the seabed when pottering along (very easy to do as you approach a beach, say).

The latest advice I have is to therefore go for the Johnson because although it is also based on the same unit, Johnson improved (widened) the cooling waterway system and use stainless steel drive pins instead.

Does anyone have recent experience of any of these outboards to comment on these points?

Thanks
Rob

 

[kgi]

agree with your issue on the shear pins, my engine was eating them, (i had the3.5 tohatsu until it was stolen) another reason the pins break is if its rough and the prop keeps coming out of the water, ihad my engine for three years never ran it in fresh water and used it in the carribean, never had a problem, i thought it was a nice little engine cheers keith

 

[vyv_cox]

I have a Mercury 2.5. Waterway blockage is a constant problem and the engine spends the vast majority of its working life, which is very limited, in fresh water. When it was used primarily in seawater it was flushed in fresh water every weekend.

My biggest gripe is that there is something drastically wrong with the paint system. Despite the fact that the engine has never been left immersed, lives most of its life on the pushpit and is stored in a warm garage all winter, I guess it has less than 40% of its original paint on it. It is 6 years old, used once so far this year, not at all last year, previous 2 years used twice or three times, but looks a total wreck. Loads of other problems that I won't bore you with.

If I was selling it, which I would love to do, I could expect very little for it. If buying now I would have a Honda 2 HP - no coolant, centrifugal clutch, 4 stroke.

 

[aztec]

why not replace the pin with a stainless one. did this on mine, still shears when you twat it, but it's more forgiving than the brass one when you are near sand or mud.

interested in stuff that needs mendin'

http://homepage.ntlworld.com/s.amos/index.html

 

[Guest]

I have a Honda 2hp.
Pros;
4 stroke so no messy oil/less pollutant
No water ways / impellers to worry about
starts every time despite infrequent use
looks like new after 18 months -never covered or stored.
came with safty cord and cut out
Cons;
noisey
easy to spill sump oil if laid down
not the lightest in class
dont like bars on clamps rather than proper thumb plates

You might want to consider one yourself

 

[tony_brighton]

I've had a lot of shear pin failures on my Tohatsu - but its only 10 secs with a pair of pliers to replace. I'm thinking about getting a steel pin but dont wnat to get one too strong.

 

[Joe_Cole]

I've got the Mariner 3.3 and am pleased with it. I did have problems with the shear pin and replaced it with a stainless one. No problem since then. It starts well and has been reliable, I also like to have the benefit of neutral gear.

I would take the story of the Johnson being the same unit but with enlarged waterways with a big pinch of salt. I would have thought that that would be very expensive to do.

Joe

 

[toad]

I have the Tohatsu 3.3 and the pin and silting up are the only problems i have had.Change the pin to stainless cost about £1 and every two years or when the teltail water decreases remove the head and clean out the waterways,this takes about 20 minutes a cross head screwdriver and a 10mm spanner.I have reused the gasket three times now so i will treat it to a new one next time if i remember,about £6 i think.

 

[dickh]

I have the early 2HP Honda, so have a water cooled exhaust. The latest ones are all air cooled with a centrifugal clutch. To avoid oil leakage you must lay the outboard down the correct way, and I always store it upright in my shed. as mine is the water cooled type I always run it in fresh water after use and so far have not had a problem with poor paint finish. Maintenance is change gbox & engine oil yearly, keep clean etc. and thats all. The Honda 2HP is on special offer thro' various chandleries at £349 I believe, see if you can borrow one and see how it performs. And they are non-polluting.

 

[Rob_Webb]

Thanks for all your replies, chaps, interesting stuff about the Mariner/Mercury/Tohatsus and also the Hondas. Does anyone have any experience of the Johnson 3.5?

 

[Douglas]

No, but I must get my oar in about the smaller Tohatsu. I have had one for about 8 years, its an absolute belter; despite being given some terrible hard treatment. Never had any problems with shear pins or cooling blockage, clean the carb bowl out every year and away you go.
It has been totally submerged three times and still fires up first pull!

 

[andy_wilson]

And they are non-polluting.

Not sure about that.

I would have thought the extra energy put in at the factory to produce all those valves, cam-shafts and oil pumps would far outweigh the slight reduction in emmissions.

 

[longjohnsilver]

Tohatsu

If I was looking to change I would go for a Tohatsu. In all the tests they always do well, owners speak well of them and they seem to cost less than the other makes.