Can`t find choke system on 50 hp 2stroke 1989 motor

[bogunnar]

I have a European Yama 50 hp. 6H5 , 50 DEO , Year 1989 (F).
Can anyone explain how the choke system works on this motor?
In my Clymer shop manual (2-225hp 2-stroke 84-89) all motors in this size have one solenoid pulling choke butterflies in all 3 carburettors.
On different web forums I can see that later motors have a "starter assy" on middle carb. My motor has neither of these and when pushing the choke toggle switch no sound can be heard round the motor.

[boscoe99]

Does your bottom carburetor have an electrical gizmo on it like shown in this illustration?

[bogunnar]

No. That is what I call a "starter assy".

See: http://www.marine-uae.ru/catalogs/ou...0beto-2004.pdf
Page 14 #33

[boscoe99]

So, your motor has choke plates?

Like this?



Here is what Yamaha has to say about the choke function:

CHOKE
When starting a cold engine, a richer mixture must be supplied to help the engine to start easily. This is accomplished by closing a choke.
When the engine is started with the choke valve closed, the air in the carburetor bore is drawn rapidly into the crankcase. This will produce a
low-pressure area or partial vacuum in the main throttle bore. As a result, fuel is drawn into the throttle bore through the main nozzle as well as
low speed circuit and mixed with the air flowing in through the hole in the choke valve before entering the crankcase.

The choke can be activated by either a pull to choke knob or by an electric solenoid. With the electric solenoid either a toggle switch or a key switch is usually used to activate it.

[almetelo]

Hi!

One of my buddys have 1994 50DEO that match with 50ELRS and the carbs are exactly as you posted on you 1st answer Boscoe.

Bogunnar I'm almost sure your motor isnīt a 1989 model as Yamaha starded the production of that model just in 1994

What makes you say is 1989 model?
What is the serial number?

Bogunnar you are looking on 50G model parts.


1994 50ELRS Yamaha Outboard CARBURETOR Diagram and Parts

Your motor doesnīt have a choke

[boscoe99]

How do you foreign (to us anyway) guys get to those parts catalogs? So much better than what we have available.

[bogunnar]

boscoe99: Choke plates? On the pics, to me they look like ordinary carb flanges.
I will inspect them next time I service the carbs. Probably there are extra holes in them, connekting them in the manifold. "choke valve" wonder where this is sitting?
Most of info I get by Googling, but sometimes via e-mejl from forum members.

almetelo: I am in Sweden and my Yama is sold in Sweden. Over here in Europe Yamaha doesn`t have same numbering system as you have in NA. Sometimes even sparepart numbers are different on same original Yamaha part.
My motor has a F punched on the motor designation plate and F in Sweden (Europe?) means 1989. This also explains why my Clymer (US) isn`t showing my choke system. Probably Sweden (Europe?) was a preproduction test market for this system?

[IMG][/IMG]

Punched "F" is on lower right side of plate, but covered with anticorrosion paste

[boscoe99]

Definitely a 1989 model year motor. That specific model was not offered in the USA.



You can see what was sold here in the US by viewing the Yamaha parts catalog at this link:

PMPro Consumer

Here in the USA, 50 HP two strokes were offered that had choke plates (1984 ~ 1988) and then with the PrimeStart device (1989 ~ later).

If your particular model does not have choke plates or PrimeStart I don't know what to tell you. Perhaps someone did a modification to the motor and changed the carburetors to something that uses something altogether different to facilitate a cold start. I think I have read about folks removing the choke plates for some strange reason. Here is an illustration that shows a carburetor with the choke plates installed.

[almetelo]

Definitely a 1989 model year motor.]

Your right!

I didnīt look carefully to the data

[almetelo]

Service manual of that motor call part #41 of carburetor

1994 50ELRS Yamaha Outboard CARBURETOR Diagram and Parts

as Fuel Enrichment Valve

which I belive to be a diferente system from choke or prime start

[99yam40]

#41 is listed as a SOLENOID VALVE ASY

Definitely different than the prime start assy used on the newer ones

Seems it is listed for 1989 to 1994 models

[boscoe99]

Your right!

I didnīt look carefully to the data

Only thanks to you.

That book can be hard to use. Easy to make a mistake.

[boscoe99]

This is better than trying to play almost any gam e. What a puzzle it can be trying to find unknown parts for unknown motors.

I don't know where I am, I don't know where I am going, I can't move, but dammit I need some help getting there. Please help.

Sorry for the space in the word gam e. System made me do it.

[99yam40]

The 35 Johnson I had before this C40 yamaha had a solenoid that squirted fuel into the single carb when you hit the switch/key for start up.
I wonder if this Yamaha solenoid valve assembly was similar and a transition from a choke to the prime start enrichment system.

Maybe someone can enlighten us on how this functioned

[boscoe99]

99yam, send me your email address please. Got some information for you.

Thx