Tohatsu 3.5 2 stroke running in... or not.

[mikehibb]

Following on from a thread last year I looked at the various options, from 2.5 up to 5 hp both 2 and 4 stroke fom various manufacturers.
After following advice on here ( plus my gut feeling) I went for the Tohatsu 3.5.

Not got it yet, placed a deposit and it is now awaiting my next visit to Turkey to be picked up.

So as I do not have the manuals yet what is the best way to run the thing for the first few hours or so? is there a running in period, do I need a different fuelil mix at first, do I need to do oil change after the first few hours run etc?

As you guessed this is my first New O/B all previous ones I have used have been second hand/borrowed, all I needed to do was add some 50:1.

Also any tips on flushing after use would be appreciated. It will be mainly transom hung and not left in the water when not in use (may be in water for a couple of day at a time max)

As always
Thanks in advance for tips.

( I bet some one will now post a link to the manual next, whoops, just googled and found it myself)

Any way, I now have the manual, but would still welcome any tips that are on offer.

 

[VicS]

[ QUOTE ]
do I need a different fuelil mix at first, do I need to do oil change after the first few hours run etc

[/ QUOTE ] Hopefully you have now decided whether you have a 2 stroke that uses a petrol oil mix OR a four stroke that uses straight petrol and has oil in a sump.

Change gear box oil annually. Water pump impeller (I'm assuming it is water cooled) every, say, 4 years

If it is a 2 stroke no harm will come of using a little extra oil in the mix during the run in period if it is not specified but don't use less than the "correct" mix. I don't know the mix but if it is 100:1 take care not to be mean with the oil ... measure it.

Best practise would be to run it in fresh water after use. I don't mean at the end of every day, great if you can though, but whenever it is not going to be in use for a few days/weeks or whatever.

EDIT: I have found the manual now. I could not find one last time I wanted one.

I see it is a 2 stroke and that it normally use 50:1 but 25 :1 during the running in period Try to use a proper outboard oil to TCW -3 spec.

I am one of those who believes in shutting off the fuel and running the carb empty when finished with for a period, it helps prevent the carb gumming up, but just let it die at idle speed, dont rev it hard.

 

[Gin]

I bought this motor last Autumn.

Your documentation will answer all your questions, but for the first 5 hours you need to run it at a mixture of 25:1( 200 mls of 2 stroke outboard oil to 5 lts. of unleaded petrol) . progressively from low revs up to the 3/4 throttle stage as marked on the engine casing.

After that the normal ratio is 50:1

 

[mikehibb]

Thanks Gin and VicS.

My colleague at work has the Mercury 3.3 version of the Tohatsu and he also recommended running the carb dry,
he also mentioned that exact phrase "it helps prevent the carb gumming up"

cheers

Mike

 

[Gin]

If you use it frequently, running it dry isn't necessary but it does stop a fuel smell in the car. Just avoid leaving the carb with fuel in it for weeks to reduce the possibility of muck build up

 

[steve28]

another trick i found was when the carb ran out of fuel, flick the choke up and start again, it will run for another 5-6 seconds which sucks that last bit up !

 

[doug748]

These are grand engines and the two main points have already been outlined ie:
Build up of salt in the cooling byways - not a problem if you run the engine regularly, otherwise flush in fresh water as outlined. If the tell tale fails to flow you might think the water pump is failing....often a piece of wire shoved up the ole will clear it. I have not attended to the pump in 15 years hard running.
Gum in the carb bowl - will lead to needle valve sticking and a flooded carb if not attended to at laying up time.

 

[rogerdog]

agree with all previous posts - also during running in don't go mad with the revs or leave it at one single rev constantly for any period (and give it a beak after say 15/10 min max for the first few to cool down) -just vary it a bit and don't go mad looking to see what it'll do.

Regular flushing is essential (I know - I've paid the price - literally in the past)

One little other thing -the running the carb empty saves no end of trouble - but don't go mad reving it to empty the carb quickly ; during this period the engine is running lean (after all its running out of fuel) and since the lube is in the oil - lubrication will have been reduced - but done sensibly works a treat