Need some help with mercontrol 1976 850 thunderbolt

[Coreykallmbah]

I’ve been trying to get my old fishing boat up and going. It’s a 76 mercury 850 thunderbolt. So far I’ve put a new everything new Ignition wise , stator , control box , rectifier , and a engine side wiring harness . It starts and runs decent in the drive way so I took it to the lake and put it in the water to see if it would run while on the trailer . Well my problem is the remote control box when pushed fwd won’t move the throttle very much . It worked one time and the rpm raised up but after that it never worked again. I check at the back of the motor and when my wife moved the throttle fwd to full speed the cable wasn’t moving the lever on the motor very much . I’m thinking something in the box broke . So I’m looking for a used box or parts or maybe even a different box that I can hard wire up to the mercury harness . Thanks for your help

 

[Chris1956]

Well, the throttle cable pulls the throttle open. So a broken throttle cable would act as you describe.

Best to remove the throttle cable from the motor and pull on it to see if it is broken.