Armature Plate Not Smooth on1975 40HP Elec. Start

[Sunken Ship]

When I reduced the throttle from 100% it hangs at around 30% where it appears to be binding on something. I adjusted the cut-out switch as I thought this was binding on the switch as it came back into contact with the armature plate. I made a video showing how the armature plate is jumping up, but I don't know if this is normal or not. Does anyone know if the plate is supposed to jump up like it is doing in this video?

I did disconnect the throttle cable at the motor and this cable is very smooth at the controls when disconnected. I lubed the entire motor with fresh grease, included the two fittings specifically for the throttle rotation.

 

[F_R]

Looks to me like something is holding it. Spark plug wires straining? I suppose it could be flywheel magnets dragging on the coils, or gummy armature plate mounting.

 

[gm280]

Looks like it could be a cam over spot with the linkage. I'd look for something at that point to see what each piece of the linkage was doing at that time to see if there is a cam over spot in the linkage... JMHO!

 

[F_R]

Gotta ask this...Do you have it in forward gear?

 

[F_R]

BTW, normal operation is to fully rotate the armature plate, then cam over to open the carburetor shaft. It appears like that is happening ok. Has to be in forward gear for that to operate smoothly.

 

[Sunken Ship]

Gotta ask this...Do you have it in forward gear?

I just double-checked and it was locked in forward gear.

 

[Sunken Ship]

BTW, normal operation is to fully rotate the armature plate, then cam over to open the carburetor shaft. It appears like that is happening ok. Has to be in forward gear for that to operate smoothly.

I checked the throttle plate (not choke plate) and it is achieving WOT, in fact it is going past WOT.