Choke problem on 4.3?

[Merc_man77]

Hey all, I have a 96 4.3 mercruiser. Started it up today for the first time this year. Admittedly so I did nothing to the fuel system to winterize it but after awhile I got her started. Idled a bit rough but seems to be running fine. Anyway I let it warm up for a few minutes and shut it back down. It will not restart unless I manually push that flapper closed on the carb. The flapper wouldent stay closed but it moved that bar its connected to to a different position. After i do that it starts right up. I'm no mechanic but I believe that's the choke and I always though if that flapper stayed open it was warm enough to start without being choked. And like I said the flapper stayed open upon restart but by manually pushing it down and it opening right back up the boat would start. Anybody have any ideas? is a sensor or something bad and telling the choke its warm enough when really not?

 

[Lou C]

That model should have an electric choke, Try opening the throttle all the way when its cold to see if it snaps shut. Inside the choke assembly is a thermostatic spring that contracts when it gets cold, that closes the choke for cold starts. There is an electric heater that warms the spring when the engine is running, that will open it in approx. 5 min run time. If it does not close the spring might be broken or disconnected inside.

 

[Scott Danforth]

you let it warm up enough for the choke to open, however not warm enough to let the motor warm up.

 

[achris]

Hey all, I have a 96 4.3 mercruiser. ...

As always, we are going to need an engine serial number. 1996 was the year the 4.3 changed from non-vortec to vortec, and with that, from heat-stove autochoke to electric autochoke...

Chris...........

 

[wrench 3]

---------The flapper wouldent stay closed but it moved that bar its connected to to a different position. ---------- by manually pushing it down and it opening right back up the boat would start.---------

I'm wondering if he's moving the accelerator pump?

 

[nola mike]

As always, we are going to need an engine serial number. 1996 was the year the 4.3 changed from non-vortec to vortec, and with that, from heat-stove autochoke to electric autochoke...

Chris...........

Really? Iirc the '89 4.3 I just stripped has an electric choke...

 

[Cobe Marine]

Really? Iirc the '89 4.3 I just stripped has an electric choke...

The 2brl carbs did use E-chokes back in the '80's. I think he was referring to the 4brl carbs which didn't go electric until they got away from the Quadra-junks and went to the Weber.

 

[Cobe Marine]

As always, we are going to need an engine serial number. 1996 was the year the 4.3 changed from non-vortec to vortec, and with that, from heat-stove autochoke to electric autochoke...

Chris...........

...and I'll add that Merc was still using up their supply of pre-vortech engines into '97 so true, serial number maters! That said, the quickest way to tell is the intake; pre-vortech has 12 bolts, vortech has 8.

 

[achris]

Really? Iirc the '89 4.3 I just stripped has an electric choke...

That would make it a 2bbl carb...