Another Selectric question - switch problems

[manny91979]

Hello all,
I have a 1971 Evinrude 50 Selectric model # 50173s. I have the very popular "no reverse" and its evil twin brother the "intermittent reverse/neutral" problem and through the info I have obtained in this forum through much searching I have narrowed the problem down to the selector switch. My plan is to take the switch apart and clean the contacts and see if that helps. So here is my question:

What mechanism does the selectric system use to ensure that reverse is not engaged at full throttle? I ask because I disassembled the control box and don't see any physical obstruction on the switch portion that would stop one from pushing the reverse button while underway in forward. My best guess would be that somehow the switch can sense RPM and not send the 12v signal to the corresponding solenoid. I am curious about this because I want to make sure that if there is some type of system, electrical or mechanical, I want to rule it out as a possible cause for my issue. For example, if it is tied to RPM, perhaps my idle is set too high for the switch to operate. P.S....yes my idle is set correctly, just using that as an example.

 

[Daviet]

Re: Another Selectric question - switch problems

There should be a plastic slide attached to the throttle lever that slides under the pushbuttons to prevent the buttons from being pushed when the throttle is advanced past a certain position.
I have seen them break off where they attach to the throttle handle.

 

[manny91979]

Re: Another Selectric question - switch problems

Thanks Daviet. I was afraid you might say that. When I disassembled the control box I see a white plastic piece loosely connected to the rear of the throttle control. It is square shaped and has a hole in it. It is way too small to reach the switches and slide into the groove in the switches. I could see how a piece of plastic would slide in there and "lock" the buttons so to speak.......

.....OK I just took a look at the parts diagram at Crowley Marine and now I see the piece that slides into the buttons. They list it as a "pushbutton yoke" and the goodnews is its available for $13.00. I cant for the life of me figure out why a prior owner would have removed it. Thanks for your help! Your description of how it works prompted me to take another look and find what I had missed the first time I looked at the diagram.

 

[Daviet]

Re: Another Selectric question - switch problems

Glad you found one. The last time i needed one I couldn't find any.
If you plan on keeping the engine, maybe buy two, sounds like a cheap price.