1981 Johnson 35 reverse only works at idle speed - cannot accelerate

[skred]

My 1981 Johnson 35 (remote) will not allow me to increase rpm in reverse. Looking at the port side of the engine, there appears to be a black plastic (?) assembly in front of the "cam" plate that pivots forward and backward. It is connected to the "cam" by a short shaft, and the assembly rotates forward and backward with the cam movement. The assembly simply "flops" around, not being connected to anything at any other point on the piece. It appears to jam against the fuel hoses when moved forward. In the attached photo closeup, you can see both the cam (white piece with reinforcing ribs), and the assembly in question to the right (has a spring around the body, and a piece of some sort of shaft at the top). The shaft appears to be broken as evidenced by the fracture marks on the top of the stub. Anyone know what this assembly is for, and how it would be attached? And, would this be the reason I cannot throttle up in reverse, since this piece appears to jam the shift cam? I've been told the throttle function is completely independent of this assembly, and is on the opposite side of the engine. So, what is it?
Anyone having a similar vintage Johnson in 25, 30, or 35 hp may be able to post a photo showing this view on their engine. Thanks in advance

http://s216.photobucket.com/user/skred/media/DSC00128_zpsbcbfdedf.jpg.html

 

[racerone]

Indeed broken and more parts missing.---It is an interlock unit and prevents high throttle in nuetral.----If kids are running the boat it might be needed.--A responsible adult would know not to start the motor in gear and to not let a 2 stroke engine wind up in nuetral.---The control box limits the amount of throttle in reverse and I see no need to have full power in reverse !

 

[skred]

Thanks a bunch Racerone! Nobody around here had a clue what that was for. I recall seeing the broken vert ical shaft piece and spring laying under the carburetor, loose. I can assume that I can run the motor without it as long as I don't start it in gear, rev it in reverse, or race it in neutral, eh? Then, I have to find where I can get that part!....