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Tohatsu M12A 12hp, the leg doesn't come off the change the impeller

S

Stelios_Rjk

New member
Hello to everyone,

New member here. I signed up after a friend's recomendation as I am messing with outboards.
At this point my problem is a Tohatsu M12A 12hp (must be 1974-1980). This model has points and not an electronic ignition.
I have undone the four nuts that holds the leg in place but the leg doesn't move. It should move and get the gearbox with the drive shaft attached to it.
I have disconected the gear changing rod. I believe the drive shaft spline is corroded or could be the water pipe stuck and cause this problem?

The fact is that after removing the bevel pinion the drive shaft can be moved up and down about 2cm. So I belive that the leg should get down about 2cm but it still remains in its place.

As it is an old engine and was in a shed for years I believe corrosion creates this problem but I don't know what to do.
I have run it for about an hour in a test bin but nothing changed. I was hopping that vibrations will free it but in vain.
Oh, I haven't find a manual or spares for this engine anywhere. Localy (Greece), or abroad.


Here are some pictures.

DSC_0410.jpgDSC_0407.jpgDSC_0408.jpg
 
Last edited:
Pretty old... You could drop an email to Tohatsu in Japan to see whether they have an old manual. Their website is http://www.tohatsu.co.jp/en/boat/sales/index.html

Odds of finding an impeller are slim. Ditto for points and condenser.

The LU may be stuck to the leg. You could try removing the power head... but again, finding a base gasket may be impossible.
 
Stelios_Rjk said:
Thanks for the response. What's the LU? Sorry, I am not familiar yet with the technical terminology.
Click to expand...

"LU" is a shortform term for a Lower Unit. Lower Unit is one of the terms used when sourcing part numbers from most OEM parts manuals for that particular location on an engine assembly.

Power head group

Top Cover group

Gearbox group etc.

Now that I have seen the last reply, something rings a bell regarding water pump impellors......................someone has re manufactured them and I have a thought he is in Australia which is probably why it was not mentioned as this is an American site.

The parts are offered somewhere very earlier in this section. Never got a response as I recall.

I will do some hunting..................

Regards

B
 
Hi C-I,

Thanks for the response, I hope you find something on the hunting!
The problem still is how to get off the lower unit.
Maybe with a strong rust remover?


Regards

S
 
once all bolts are undone get a slide hammer and attach it to the very lowest part of the leg and dont go mad but just keep using the slide weight to free it off.
the engine is a mid 70's, but that dont make it any worse than a mid 90's or even 5 years old if the drive shaft is stuck then its stuck.
sometimes these just never come off and the engine is scrap,sometimes its a case of gently does it over a long period of time.
the last thing you need is to destroy anything as parts are impossible to find,not difficult impossible.
tohats is a terrible engine for parts and back up full stop.
if over 5 years old the company dont want to know at all about anything.
but these are great engines and can be got running and suprise a lot of people when they have them tuned good.
no pint in spray anything up the shaft as if the case is not spliting youl never get anything on the shaft anyway.
heat dont work, ive been down that road, but gently applying a few hits with the slide hammer can do wonders.
i would first hang the engine from a beam as you dont want it back on the floor untill this is out.
and when you give up for the day you just leave it hanging with a weight on the bottom.
this could take an hour, but could take everyday for 3 weeks ha ha yep no kidding it can be a long old job.
once its out i would then give the shaft a real good going iover with a wire brush, and then clean out the part it attaches to.

hope some of this helps

phill
 
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