Push key = electric choke?

[scoutabout]

My '04 Yamaha 90 4-stroke has an ignition switch that pushes in as well as turns. On some of the Mercs I've owned in the past this was how you engaged the electric choke. Same with the Yam or is the ecu supposed to meter the chokes automatically?

I ask because:

a) there is no sound of the butterflies snapping shut when I push the key in while in the on position (with the Mercs this sound was easily detected)

c) pushing the key in doesn't seem to make any difference to how the engine starts when cold (which sometimes takes more cranking than I would have expected for an engine with only 23 hours on it)

opinions?

 

[imported_Curmudgeon]

Re: Push key = electric choke?

Most likely your 4S is fuel injected. Assuming so, there are no "butterflies" and the "push" function is non-functional ...

 

[JUSTINTIME]

Re: Push key = electric choke?

u should have no choke on efi motors

 

[scoutabout]

Re: Push key = electric choke?

Four shiny carbs under the cowl boys -- so no efi. As I recall the 90 went efi in '05...At least in Canada.

I should have checked this key activated choke business before I put her away for the winter. Now I've got six months to ponder the question and stew.

 

[bigbrownbuku]

Re: Push key = electric choke?

the choke function is not installed on the engine as it is choked electrically. its the missing pin in the main harness, engine side?

 

[scoutabout]

Re: Push key = electric choke?

By "electrically" do you mean automatically? Or is some operator input required?

Sorry, bbb -- I don't get your reference to the harness. Can you clarify?

 

[rodbolt]

Re: Push key = electric choke?

as I was not intending to ever post here again and I have to move anyway all my manuals and guides are packed.
look on your carbs, this should be a prime start motor. it should have 2 white cylinders with 2 wires coming out of each. one on the top carb and one one the 3rd one. if it does its prime start and the push to choke function is inoperable.

 

[scoutabout]

Re: Push key = electric choke?

as I was not intending to ever post here again and I have to move anyway all my manuals and guides are packed....

..er sorry to hear that. What gives?

...
look on your carbs, this should be a prime start motor. it should have 2 white cylinders with 2 wires coming out of each. one on the top carb and one one the 3rd one. if it does its prime start and the push to choke function is inoperable.

Wow, man -- thanks! Too bad my boat is 250 miles away buried in a shed til spring, but that's some VERY useful info.
So, having known you for all of 9 seconds, let me say:

a) don't go
b) if you don't, would you mind giving a brief rundown of how this "prime start" function works when the engine is cold?

Thanks.

 

[rodbolt]

Re: Push key = electric choke?

on the US versions of that motor with prime start its fairly simple.
the small white cylinders have a wax pellet that expands and contracts with varying air temps. as it expands and contracts a needle moves up and down to allow a richer or leaner mixture. the heater is powered by 12v key on power.
if the throttles are opened very much at all the system cannot work as designed.
its very sensitive to venturi vacum. to much throttle opening and there wont be enough vacum to allow for pulling the extra fuel and will result in a very hard to no start condition.

 

[scoutabout]

Re: Push key = electric choke?

OK, thanks -- so you're saying go easy on engaging the neutral fast idle initially on cold starts?

 

[rodbolt]

Re: Push key = electric choke?

I am saying dont use it, if it wont start at idle as designed its broke and needs to be repaired.

 

[scoutabout]

Re: Push key = electric choke?

Gotcha! 8)