hi,
Looking for some advice. Have a 3.4m tinny. Just looking to purchase a new outboard 4HP. Should I be looking at a 4s or 2s .
Is there a better option for this size outboard ?
i want reliability . Is the 4S Yamaha 4hp better than the 4HP 2 stroke ?

appreciate opinion

I bought 4 stroke brand new Suzuki 4HP , but have constant problems with starting up, even stopping during runs.
Next was Tohatsu 18 HP 2 stroke and works like a dream, first start every time.
I use on similar aluminium dingy 3.6 meter

dont want to register . Purpose is for my son to use it mainly in NSW rivers when on holiday and I dont need to supervise.

In my opinion 4 stroke will be safer for small motor. My worst nightmare is to flood / wet spark plugs when starting cold motor. Too much choke for too long and no hope to start it without removing and cleaning spark plug., What is not so convenient once on the water in harsh conditions. Even with my 18 HP Tohatsu I need experience to come with very precise routine to use minimal amount of choke.
I heard that Suzuki are difficult to start, so other brands could be much safer.
For me it looks like some fault in design because water get easy into carburetor when spryig around at speed and get sucked it into carburetor in my Suzuki.
I had to take my carburetor to parts and clean it carefully. Now is working perfect every time but need to take exceptional attention that water will not spray onto motor

four strokes in that size class are a waste of money. the only advantage is less fuel usage, which is infintessimal in that hp anyway. the disadvantages of a four stroke are many. mush more weight, less portable, cannot store or caryy side on, gutless, more moving parts, more difficult to service, twice the price.
two stokes of a reputable brand are fine and will start easily. i wouldnt put too much stock in marco's limited experiences.

I've always preferred 2 stroke for small engines and 4 stroke for the over 90 hp..
If you're going to do minimal supervision, then make sure he has a spare power pack (oars), and knows how to row to the river bank. Any engine has the capacity to stall mid run, or be difficult to initially start, and in the first panicked moments, the engine can easily be flooded.

I used to drive a tinny to school every day, and the freedom that boat gave me was sensational..

Select to expand quote

Jag2 said..
dont want to register . Purpose is for my son to use it mainly in NSW rivers when on holiday and I dont need to supervise.

The size of engine is no matter for rego purpose, with a 4 HP you don't need license to operate the boat still needs HIN and rego.
Got done on the river with my inflatable (tender for my yacht) and a small electric motor, water police told me to get it out of the water and as it was a tender had to be operated less than 500m from the main vessel or put HIN and rego.
I have a 10ft tiny and runs it with a mercury 2s 15HP she flies, love that outboard has gearbox at the tiller and start first pull all the time, I had a similar one before but 8 HP and was as good.

Good advice above and I'd also go the 2-stroke. Keep in mind that a low powered motor in the ocean can be very dangerous as you can't 'outrun' waves and if you need to take evasive action you need more grunt. Small motors can sometimes be useless in strong winds too.

Thank you all . I am even more confused now. We are going to stick with a 4HP . We are only using in river . It's a car topper so I don't want to habe a bigger motor.
So at the end of the day , 2s or 4s is what I am asking . price aside . What's best for reliability

2 stroke...

2 stroke would be the way to go just keep the fuel clean and clean down motor after use and you should be fine

2 stroke all the way.

lighter
reliable
simple
long term cost effective.... eg: servicing
more top end - can beat the current. Seen a few tinnies go backwards.
smell......mmmmmmm 2 stroke
initial price

So the 2s will out run the 4s ? are they that much different .
cost wise I can purchase a new 4s cheaper than its 2s equivalent

take everything else on board . Appreciate the feedback

2 stroke