Merc 165 Electric Choke Conversion - Rochester Carb

[kckranz]

I had a rusted out stove pipe to heat-type choke actuator so decided to convert to electric choke, which works great, however there is a linkage arm that runs from the choke shaft down and connects to the fast idle cam that functions as an idle screw stop. At idle, the screw rests against the stop, but this makes it so the choke shaft above cannot rotate. This is okay, as long as the choke is in the position you want it when you are ready to idle. This doesn't seem right to me, for example if you turn off the engine at idle (warm engine choke fully open), the cam stop will not allow the linkage to rotate the choke shaft closed for the next cold start. Wonder if I am missing something, or perhaps that linkage arm should be removed when converting from hot air to electric choke.

In the attached photo, the linkage is #7, cam is #22, stop screw is #26.

 

[harleyman1975]

Yup remove the linkage.

 

[kckranz]

Upon closer inspection, the choke shaft is connected to two rotating hands, which operate independent of each other. This seems to allow the choke to move "at will" to a point where there is a tab on the hand with the linkage down to the fast idle cam, which limits it's travel. Not sure the function of this design.

I will play around with the setup a bit, possibly removing the linkage and observer the behavior.

 

[kckranz]

Confirmed. Linkage needs to be removed for the electric choke to work properly.

 

[kenny nunez]

Be sure to not remove the cam that the idle stop screw contacts. You may have to add a a washer to it to lock it in place.

 

[alldodge]

Confirmed. Linkage needs to be removed for the electric choke to work properly.

My opinion is it doesn't need to be removed. The choke will not engage unless the throttle is pumped at least once when the engine is cold. Pumping the throttle allows the spring in the choke plate to close.