Yamaha 4 hp 2 stroke outboard. Hasn't been run in many years but was running fine when last used
What would I need to do before attempting to start it?

fred wrote on 11/07/2018 :
Yamaha 4 hp 2 stroke outboard. Hasn't been run in many years but was running
fine when last used
What would I need to do before attempting to start it?

Easy job - take the head off and take a look at the condition of the
bore(s). If that looks OK, drain any fuel, clean the carb out and its
jets, air-filter, spark plug(s). Reassemble, add fuel and start it.

On Wed, 11 Jul 2018 09:25:47 +0100, Harry Bloomfield
wrote:

fred wrote on 11/07/2018 :
Yamaha 4 hp 2 stroke outboard. Hasn't been run in many years but was running
fine when last used
What would I need to do before attempting to start it?

Easy job - take the head off

I wouldn't go that far as you might need to / should replace the head
/ base gasket (if it has a separate head and barrel) and they may not
be easily available, especially outside a complete gasket kit.

and take a look at the condition of the
bore(s).

You can do that cheaply and easily these days with an endoscope that
plugs into your laptop or smart phone. However, if you remove the plug
and peer in the bore with a torch you might get a general idea of the
condition and if you spray some light oil into the plug hole and then
gently try turning it over by hand, you should get an idea if it's got
any problems or not (and you might know if it was laid up properly the
last time it was used and how / where it was stored etc).

If that looks OK, drain any fuel,

Agreed.

clean the carb out and its
jets,

It may not be necessary, easy enough to try first.

air-filter, spark plug(s).

Yup. They often don't have an air filter as such or only have a course
oiled sponge type that, if in good shape would just need rinsing out
in paraffin and re oiling (engine oil will do).

Reassemble, add fuel and start it.

Also check the lower leg / final drive doesn't contain any water and
drain / re-fill with the right grade oil. You may need to test run it
in water or it might damage the water pump impeller, if it's water
cooled (and the chances are the leg would be, even if the cylinder was
fan / air cooled).

I'd go for 50:1 2/ mix of an outboard 2/ oil, 10:1 if it was a British
Seagull. ;-)

Cheers, T i m

On 11/07/18 08:31, fred wrote:
Yamaha 4 hp 2 stroke outboard. Hasn't been run in many years but was running fine when last used
What would I need to do before attempting to start it?

empty out all old petrol

wash out clunk or fuel filter if it has one

Fill with new petrol

Start. If it doesnt THEN start disassmbling and cleaning

--
€œProgress is precisely that which rules and regulations did not foresee,€�

€“ Ludwig von Mises

On Wednesday, July 11, 2018 at 9:59:07 AM UTC+1, T i m wrote:
On Wed, 11 Jul 2018 09:25:47 +0100, Harry Bloomfield
wrote:

fred wrote on 11/07/2018 :
Yamaha 4 hp 2 stroke outboard. Hasn't been run in many years but was running
fine when last used
What would I need to do before attempting to start it?

Easy job - take the head off

I wouldn't go that far as you might need to / should replace the head
/ base gasket (if it has a separate head and barrel) and they may not
be easily available, especially outside a complete gasket kit.

and take a look at the condition of the
bore(s).

You can do that cheaply and easily these days with an endoscope that
plugs into your laptop or smart phone. However, if you remove the plug
and peer in the bore with a torch you might get a general idea of the
condition and if you spray some light oil into the plug hole and then
gently try turning it over by hand, you should get an idea if it's got
any problems or not (and you might know if it was laid up properly the
last time it was used and how / where it was stored etc).

If that looks OK, drain any fuel,

Agreed.

clean the carb out and its
jets,

It may not be necessary, easy enough to try first.

air-filter, spark plug(s).

Yup. They often don't have an air filter as such or only have a course
oiled sponge type that, if in good shape would just need rinsing out
in paraffin and re oiling (engine oil will do).

Reassemble, add fuel and start it.

Also check the lower leg / final drive doesn't contain any water and
drain / re-fill with the right grade oil. You may need to test run it
in water or it might damage the water pump impeller, if it's water
cooled (and the chances are the leg would be, even if the cylinder was
fan / air cooled).

I'd go for 50:1 2/ mix of an outboard 2/ oil, 10:1 if it was a British
Seagull. ;-)

Cheers, T i m

Many thanks for the informative replies. I think I'll try Tims way first and then go from there

In message , fred
writes
Yamaha 4 hp 2 stroke outboard. Hasn't been run in many years but was
running fine when last used
What would I need to do before attempting to start it?

Based on experience with Seagull outboards, I'd agree with advice to
wash out fuel tank, carb etc. Check gearbox oil. Inspect plug, one brief
squirt of 3-in-1 from aerosol can into plug hole then check for spark.
If no spark, check magneto contacts.

If water cooled, find clean wheelie bin, part fill with water and try to
start in that. Run slowly to clean out any old salt from waterways.

Let us know how it goes, as I have an old Seagull and an old Volvo Penta
to sort out here.
--
Bill

T i m formulated the question :
I wouldn't go that far as you might need to / should replace the head
/ base gasket (if it has a separate head and barrel)

'Might', but probably not. I had several 2T's and regularly took the
heads off to clean off the carbonisation and never saw a need to
replace the gasket on a 2T, providing it was carefully refitted in
exactly the same location as it came off. A 4T I would definitely
replace the head gasket, because their gaskets are so much more
complex.

T i m formulated on Wednesday :
clean the carb out and its
jets,

It may not be necessary, easy enough to try first.

The petrol oil mix, will have evaporated out over the years, leaving a
bit of a mess in there. Even stored for just a few months, the carbs
can choke up on 2T's.

On Wed, 11 Jul 2018 14:32:42 +0100, Harry Bloomfield
wrote:

T i m formulated the question :
I wouldn't go that far as you might need to / should replace the head
/ base gasket (if it has a separate head and barrel)

'Might', but probably not.

But given that it may not be necessary to even disturb anything, why
add more complication / risk?

I had several 2T's

How many of them were outboard motors OOI?

and regularly took the
heads off to clean off the carbonisation

Funny. I've run many 2/'s over many years / miles and rarely done
that. Maybe you were using the wrong lubricant or not running them
hard enough?

and never saw a need to
replace the gasket on a 2T,

The option to re-use gaskets on any machine can be down to their
function (ignoring re-usable designs, like the rubber gasket type)
.... if they are just to 'soften' a metal to metal contact and/or
provide a set thickness spacer, rather than form an oil / compression
seal and assuming the old gasket comes off cleanly in the first place
etc.

providing it was carefully refitted in
exactly the same location as it came off.

Worth a go but again, rarely ideal (considering the above etc).

I *could* have re-used the thermostat housing gasket on the kitcar the
other day but because I'm a good wrench, I made and fitted a new one
because that was the right thing to do. ;-)

A 4T I would definitely
replace the head gasket, because their gaskets are so much more
complex.

As are bigger water cooled 2/ outboard motors. ;-)

Cheers, T i m

On 11/07/18 14:39, Harry Bloomfield wrote:
T i m formulated on Wednesday :
clean the carb out and its jets,

It may not be necessary, easy enough to try first.

The petrol oil mix, will have evaporated out over the years, leaving a
bit of a mess in there. Even stored for just a few months, the carbs can
choke up on 2T's.

They can, but new petrol in there usually dissolves the gums.
I've had a couple of clinks needing washing out and blowing clear, but
by and large all is OK

They smoke on first start and the plugs may need a bit of cleaing after
an hours running, but that's all.,

These are simple beasts really.

And I don't hold with taking them apart at the cylinder level. If they
are corroded down the bores, its rebuild time whenever you discover it.
Why not take the chance its OK, becase trying to start it wont wreck it
beyond where it is now.

And you want be able to turm it over if its siezed anyway.


--
Canada is all right really, though not for the whole weekend.

"Saki"

On Wed, 11 Jul 2018 14:39:28 +0100, Harry Bloomfield
wrote:

T i m formulated on Wednesday :
clean the carb out and its
jets,

It may not be necessary, easy enough to try first.

The petrol oil mix, will have evaporated out over the years,

Are you sure you aren't treating everone as yourself? What if the
engine had been laid up properly and the carb / tank drained, what
would there be to clean out? The OP didn't say it wouldn't start, just
what might he check before trying to start it as it was running fine
the last time it was used?

leaving a
bit of a mess in there.

See above.

Even stored for just a few months, the carbs
can choke up on 2T's.

Or not, the many 2/ outboards I've had and used over the years that I
just check over, fill with fresh fuel and have then start on the first
or second pull and run as well as the day I last used them?

Even if I might use an outboard again next week, unless I was leaving
it on the back of the boat for the period, I would typically run the
carb dry because I would be putting it in the back of the car and not
want petrol (or even fumes) everywhere.

But you are right and especially with more modern fuels with other
additives, *if* the system was left full of fuel / fuel-oil mix for a
prolonged period, you *could* get gumming etc (depending on the
sensitivity or design of the engine / carb).

Our last 2/ motorcycle was a 2/ but autolube so (and sometimes was)
left unused for many months, only to start and run on the first or
second kick.

My little Yamaha 2hp 2/ outboard was often not run for *years* and
would then start on the first real pull of the cord.

Cheers, T i m

p.s. I've also had quite a few 2/ model engines feel completely gummed
up after a long period idle but then free quickly with a bit of fresh
fuel and run fine once started. But again I didn't leave the tanks
full of fuel after use.

On Wed, 11 Jul 2018 11:47:02 +0100, Bill wrote:

In message , fred
writes
Yamaha 4 hp 2 stroke outboard. Hasn't been run in many years but was
running fine when last used
What would I need to do before attempting to start it?

Based on experience with Seagull outboards, I'd agree with advice to
wash out fuel tank, carb etc.

.... Assuming it wasn't done when the outboard was last used ... ;-)

Check gearbox oil.

Yup. It could well have been 'dry stored'.

Inspect plug, one brief
squirt of 3-in-1 from aerosol can into plug hole then check for spark.

I'd see if it starts before doing that.

If no spark, check magneto contacts.

If it won't start and with a drop of fuel squirted into the plughole /
inlet it won't start, check for spark.

If water cooled, find clean wheelie bin, part fill with water and try to
start in that.

Check.

Run slowly to clean out any old salt from waterways.

Might be too late if you are doing it *then*? ;-(

Let us know how it goes, as I have an old Seagull and an old Volvo Penta
to sort out here.

If laid up properly, check / apply gear oils, fill with fuel, enjoy.
;-)

Cheers, T i m

p.s. Take the Seagull prop off and check for the remains of fishing
line on the prop shaft and output bearing. ;-)

On 11/07/2018 08:31, fred wrote:
Yamaha 4 hp 2 stroke outboard. Hasn't been run in many years but was running fine when last used
What would I need to do before attempting to start it?

Personally, I'd whip the plug out, see if it turns over easily and if
not pour in half a cup of oil, orientate the engine so that the top of
the piston is horizontal, and leave it to soak for a day or two.

If it turns over, check the air cleaner and try it with a bit of fresh
fuel and a new plug. Check that you have a spark first. You may be
surprised how well it runs.

If it won't start, the carb may need cleaning out because of oil and/or
dirt blocking the jets.

I wouldn't whip the head or cylinder off unless I could not turn it over
at all.