Choosing new small outboard. Honda 4 stroke or Mariner/ Yamaha/ Suzuki 2 stroke

Using 2 stroke on lakes and rivers??, its criminal. They are dirty, unreliable, and thirsty. Get a 4 stroke 3.5 hp Tohatsu/Mariner/Mercury (same engine), powerful, economical, clean, quite, no need for fuel mixing nonsense, environmentally friendlier; but heavier; however, you are not going to carry the outboard for miles are you? If you have the budget, go for a new outboard; the second hand are expensive for what they are and old; reliability is key.
 
I had a Mercury 2.2 2 stroke, which was good, tiny powerhead, and very light, but had no neutral, so was a pain, especially as you have to run it out of fuel when putting it away, to stop the jets clogging up with fuel residue.

I replaced it with a new Mercury 2.5 4 stroke, which starts and runs very well indeed, and it has a neutral, which is very nice. Servicing is a doddle, and I don't have the stale two stroke fuel issues, nor having to carry any of the wretched stuff...

On balance, as lovely as the little 2T was, the 4T beats it by a whisker.

Avoid the Chinese stuff, and the tiny Honda air cooled unit, which is a dog. Yamaha and Suzuki are fine ASAIK
 
CAPTAIN FANTASTIC said:
Using 2 stroke on lakes and rivers??, its criminal. They are dirty, unreliable, and thirsty. Get a 4 stroke 3.5 hp Tohatsu/Mariner/Mercury (same engine), powerful, economical, clean, quite, no need for fuel mixing nonsense, environmentally friendlier; but heavier; however, you are not going to carry the outboard for miles are you? If you have the budget, go for a new outboard; the second hand are expensive for what they are and old; reliability is key.
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Captain Fantastic,

I think we'll have to agree to differ.

I'd say 2 stroke engines are not dirty, it's easy to work out a mixture meaurement bottle ( I have a tiny old whisky bottle which when filled with modern relatively eco friendly oil once gives 100:1, were not talking of the Torrey Canyon or Exxon Valduez here ) and as for weight, it's not a case of carrying the thing for miles, it's lifting it on and off the dinghy, especially if ones' better half has to do it while one lowers it down to her.
 
well...

Seajet said:
Captain Fantastic,

I think we'll have to agree to differ.

I'd say 2 stroke engines are not dirty, it's easy to work out a mixture meaurement bottle ( I have a tiny old whisky bottle which when filled with modern relatively eco friendly oil once gives 100:1, were not talking of the Torrey Canyon or Exxon Valduez here ) and as for weight, it's not a case of carrying the thing for miles, it's lifting it on and off the dinghy, especially if ones' better half has to do it while one lowers it down to her.
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I am worried about the eco-terrorist/nutter/green freak label but if you look at the third par from the quote in this document you will see that the scale of pollution from us leisure boaters is on a par with a decent tanker spill. As I understand it one of the extra problems with two strokes is not just that it throws unburned oil and petrol into the water but the partial burn means that many of the long chains are partially cracked so they emit a soupy fog of a splendid range of nitrates and benzene.

feel free to tell me that the stats are bollox but I think that the science is pretty clear - just as it was on TBT

However, if you like the smell, can't remember which way to lay the outboard down then at the moment it is legal to use them.

Seajet is dead right though... not all two strokes are as bad as each other - some are much, much worse.



http://www.tc.gc.ca/eng/marinesafety/debs-obs-resources-publications-protecting-menu-873.htm

Diesel, gas, and petroleum lubricants are harmful for the environment. Boat engines, automatic bilge pumps, fuel handling facilities, and accidents are responsible for spilling a great quantity of oil and fuel. The tremendous volume of hydrocarbon and oil pollution entering North America's waters every year from recreational boating is estimated to be more than 15 times the amount of the Exxon Valdez spill (up to one billion litres per year).

Two-stroke engines are the most important source of a persistent form of pollution that has devastating effects on the aquatic environment. An estimated 30 percent of all fuel and oil used in two-stroke engines ends up in the water. Exhaust fumes from both two- and four-stroke engines are of concern because these engines usually lack any form of emission control.

There are approximately three million pleasure craft in Canada, most with two-stroke engines. Taken individually, their impact may be small; collectively it is a major concern. Manufacturers around the world are responding to this concern by developing four-stroke marine engines, lean-burn two-stroke engines, and fuel injection systems, which greatly reduce the amount of oil and fuel entering the water and air emissions.
 
lustyd said:
Why? You think that haze coming out of it's ass is fairydust?
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Well all I was taught is modern 2 strokes emit nothing but squirrels' tears, and if dunking a 4 stroke doesn't that have more, heavier lube oil than 2 stroke ( yes, smaller amount of gearbox oil admitted ) ?

Still not as painfull on the environment as SWIMBO's supersonic shrieking as she goes over trying to handle a heavy 4 stroke though. :)
 
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Hmmm planty for me to think about here. I do appreciate the environmental concerns about the two strokes. Having said that I dont expect mine would do much running time, perhaps a few hours a year. The weight (and cost)of the 4 strokes mentioned does concern me. Individually a few extra kilos might not be much, but on top of the electric trolling motor, batteries solar panels and heaps of other gear I was trying to go for the most compact and light I could find. It was for this reason I looked at the 2 Hp 4 stroke Honda, it only weighs about 12-13kg. Other manufacturers seem to be catching up with the small and light 4 stroke theme. Problem is I really cant justify buying new for the level of usage, so am after something second hand and affordable. Maybe in a few years the second hand market will be more competitive. The Honda doesnt get very good reviews here though!!!

I could just carry on with the seagull ;)
 
Tohatsu

alahol2 said:
Citation required...
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bless you for your doubts

it is a truth universally acknowledged etc etc

and I doubt that evidence will make anyone change their mind

where would these fora be if proof was required all the time?

however

here is a nice table from Tohatsu - that well known eco-terrorist organisation

http://www.tohatsu-outboards.com/fuel-consumption.htm

which suggests that the 5hp two stroke uses 2.5 litres per hour whereas a similar size four stroke uses 1.7

mentioning fuel consumption was an attempt to appeal to my fellow boaters self interest

after all by shifting from a polo to the series 5 BMW to shift my outboard around then I would obviously be burning more fuel than any the outboard would chuck away

but it is really the pollution from these things

while digging around the data I found a study from the USA that suggested that one two stroke motorbike chucked out the same pollutants per mile as 50 cars - I assume it is not counting C02 but Nox and CO

however, having witnessed the fight my fellow sailors put in to defend the use of the crustacian sex changing TBTs then appealing to their caring natures can often seem to be a bit of a fruitless enterprise



as for the dropping the thing overboard and the oil pollution from the sump

very interesting point

a bit facile if you ask me

but by dropping it over the end of the boat would mean one sump full of oil in the briny whereas the two stroke chucks the oil and much worse into our lovely waters every minute it is running through its 20, 30 or 40 year life span

there is also the argument about the environmental costs of replacing old with new

which has more merit as an argument

well any outboard you take to the dump will be recycled so that saves the cost of digging out more aluminium

the last stuydy I looked at suggested that the scrap value of an outboard is around $200

so recycling it will go some-way to mitigating the environmental impact or remanufacturing that aluminium into a new outboard and that improved fuel efficicny over the following decades is likely to mitigate the environmental impact of the new engine

but the main point is that the four stroke chucks less toxic crud into the estuaries and rivers we enjoy sailing on than two strokes


but then with a four stroke you don't get that lovely smell, the lovely blue haze, the lovely sound


swings and roundabouts


but in my opinion it really is time we did the decent thing quit using the things

yours

the tree hugging gay eco hipocrit
 
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VicMallows said:
Because some of us like to verify the provenance of such statements rather than just taking them at face value. "A" survey said....etc.
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You assume I took it at face value but OK, a bit of science guesswork then.

Moving a boat at a given speed requires the same work whether it be 2 or 4 stroke
4 strokes, in almost every single test have been shown to use less petrol
if the 2 stroke was actually usefully burning the oil it would require less petrol, not more

Energy in = energy out -> thermodynamics and conservation of energy

The extra energy in (oil and extra fuel) on the 2 stroke isn't being used for pushing the boat, therefore there are a few possibilities:
  • The noise of a 2 stroke uses huge amounts of extra fuel
  • 2 strokes heat the water considerably more than 4 strokes
  • 2 strokes actually ditch the extra fuel and oil into the air and sea

I'm fairly sure the exhaust temp is similar on my engines, and the noise isn't that energy sapping. I do, however, see smoke from the 2 stroke, and the occasional bit of fuel/oil in the water. The difference in the fuel economies will be the excess being put into nature more or less, and I'd say that's significant when boaters all over the world are using them.
 
We have had a 2hp Honda (predecessor of the current 2.3) for a number of years whilst circumnavigating. It has probably had 10x the use of many such motors and has proved reliable.

BUT attempting to rectify a fault recently which was due to corrosion suggested that there was insufficient corrosion protection to describe it as a 'marine' engine. Presumably the basic motor is used in many non-marine applications and simply put into the outboard casing without much modification to suit the marine environment.
 
my Honda has been great too

blenkinsop said:
We have had a 2hp Honda (predecessor of the current 2.3) for a number of years whilst circumnavigating. It has probably had 10x the use of many such motors and has proved reliable.

BUT attempting to rectify a fault recently which was due to corrosion suggested that there was insufficient corrosion protection to describe it as a 'marine' engine. Presumably the basic motor is used in many non-marine applications and simply put into the outboard casing without much modification to suit the marine environment.
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mine has been very reliable............ so far

the neutral is very useful and being air cooled means that if it comes out of the water for a while it takes no harm

the other advantage is that when I run it in the engine well the hot air heats the cockpit!

I would buy another one if I kill this one

at the moment it lives in the stern locker on its side and comes out once a month for a fire up.

it is my back-up engine

it is stupidly fuel efficient

last year we used it to drive the slug up the nene - mirror offshore triple keel - 4.5 knots at full blatt

40 miles there and 40 miles back - some sailing but mostly the outboard - and used a gallon of fuel

it runs really well on low revs without clagging up

it is noisy.... but aren't they all?

of course if you love the smell, the sound and the smoke from a two stroke......
 
Seajet said:
Still not as painfull on the environment as SWIMBO's supersonic shrieking as she goes over trying to handle a heavy 4 stroke though. :)
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I see that the Suzuki 4stroke 2hp is 13kg; see here: http://www.suzuki-marine.co.uk/outboards/detail.php?ref=DF2.5S&y=07 and that is the same weight as my Mariner 3.3hp 2 stroke see here: http://www.mariner-outboard.com/mariner/en/products/products.aspx?Model=TwoStroke 3.3

I think the time might be coming for a rethink and a move away from 2 stroke.

rob
 
I've had a Yamaha 2.5 hp 4 st for about 3 years.
It's heavy, 17 kg.
The fuel filler cap lets water leak into the tank.
The carb. Jet blocks with even the tiniest bit of moisture in the petrol.
Two bolts hold on the air box, the carb, two gaskets, a spacer, all at the same time....try reassembling that lot.
The choke pull has broken.
The top locks have broken.
It's very hard to start in cold weather.

......it's manufactured in France, say no more!
 
dylanwinter said:
Honda 2.3 - weighs 12.7kg

runs like a top

never failed
D
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Famous last words?

We are on our second Honda BF2D. Most of the time it is absolutely fine, but the carb clogs up with water from time to time, although the engine is kept covered and I am paranoid about using clean fuel. Cleaning the carb when hanging over the back of the dinghy probably dumps more hydrocarbons into the environment than a hundred Seagulls....
 
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