1977 70hp Evinrude - Shift Trouble

[kyleIHC]

After coming across a relative's 15ft jonboat and the associated motor, he offered to let me take it and see if it ran out and pumped coolant, while he discussed a price with his sister. So it's been at my house for about a week now. It does pump coolant, though there seems to be a leak above the water pump out of the case, as I can see it running from the pivot point. Still, I have a strong, steady stream and haven't witnessed a single hiccup in flow.

The only real problem I could find, aside from limited legroom at the wheel, is that yesterday while running it in a tank of water I got the shifter stuck in forward. Then I got it stuck in a position right next to neutral, and it wouldn't even go very far forward again.

So I popped apart the case, found that everything was generally dirty and looked 33 years old. Loosened the friction brake and began to clean up. Checking each component as I disassembled, I found that the "sticking" problem lies in or around the small disc-and-plastic-cam that manipulates the throttle lever. It was still "stuck" until I removed this unit, and it was stuck in a position where the detent ball was "riding high" between depressions on the unit. I cleaned up a bit, re-greased with tacky machine grease, and reassembled. This fixed the problem, until I put it in gear again.

I did this half a dozen times, and the final time I used less torque on the actual bolts holding the case together, after finding out that the pivot point for the internal throttle cable lever was showing heavy interference on the grease I applied there. Now it shifts fine, and I haven't gotten it to bind up again even after running it a final time. So it's possible I just had the case tightened too much, but I figured I'd ask here: Is something casing this problem (like a bent detent spring or the wear groove in the detent positions) or have I figured it out - too much muscle on the shifter case bolts?

I appreciate any response!


Kyle

 

[tashasdaddy]

Re: 1977 70hp Evinrude - Shift Trouble

picture of you controller. sounds like you may have the wrong one. you also have a electric, or hydro-electric shift system.

what is the model # of the motor? so we are sure what you have.

if it is a 1970, i would be considering passing on it. the parts are hard to find, and expensive.

 

[Numlaar]

Re: 1977 70hp Evinrude - Shift Trouble

TD the motor is a 1977 (not a 70), and should be fine. I have the same one, same set of controls... It's really difficult for those controls to wear out in the actual box... I did the same thing on mine, took it completely apart, lubed everything up, and stuck it all back together, and they are fine.

(My issue was teh cables binding, depending on how they were routed, not sure if that relates to yours).

But once rebuilt, you should be good to go. You may need to eventually replace the cables, as like the steering one, there is no way to lube them internally.

 

[kyleIHC]

Re: 1977 70hp Evinrude - Shift Trouble

The model: #70773S

Here are a few pictures, starting with the control lever:

The cable paths:

Linkage at the engine:

And I've noticed that the timing connection isn't going "full retarded" as shown in this picture:

I don't plan on messing with any of this until I can get ahold of a service manual, but money is a limiting factor. And again, the control handle is stuck in "forward" in all of those pics. The detent will not snap into neutral, no matter how much cable massaging and moving I do.

I'm leaning towards these cables being the cause of the issue, because I've taken apart and inspected the entire unit a half dozen times. I guess it could use a more thorough cleaning, but none of that seems to matter - as I said, the thing is still "stuck" until I remove & replace the two-way cam plate that operates the throttle lever, and works with the detent ball and spring to lock positions.


Another quick question I didn't think to ask before - does anyone with experience with these motors notice that the throttle doesn't "pick up" until you're halfway to the full extent of travel? This is something I noticed on this particular boat, but then again I could just be out of adjustment.


EDIT:

Just as a side note, I have also witnessed much "friction" at the motor's end of the deal, this being "sticky" advance plate operation and generally slow movement and sometimes a premature stop.

 

[kyleIHC]

Re: 1977 70hp Evinrude - Shift Trouble

Well, I still don't have a price on this boat & motor combo, but I did get to test it out yesterday on lake Wappappello, in Missouri. I also sat through a rather intense demonstration; this covered points such as noting a lower-than-normal pool in small lakes AND how to polish your propeller in the shallow spots.

It ran fine when not in sand, and throughout the day the controls behaved fine... after an initial hangup & disassembly at the large ramp.

Then, when moving it on the trailer, the controls locked up again, and are currently still limited to only "forward" and in gear, meaning the NSS is not depressed. So no start.


Any ideas? I'm positive there is no error in how this thing is assembled, I have a recent bout of rather good experience. I am also fairly sure that cable binding is not an issue.

 

[tashasdaddy]

Re: 1977 70hp Evinrude - Shift Trouble

your cable turns are too tight, cable too short.

 

[willamettejeff]

Re: 1977 70hp Evinrude - Shift Trouble

I have a 1978 70hp Johnson. It is normal to be able to pull farther back on the ignition advance lever. This lever is spring loaded and once fully advanced at full throttle is designed to stay that way even when throttle is backed off to 3/4 throttle. This is the most efficient running position. It is also normal for the carbs not to open until about half throttle. What is important is when throttle lever on the controller is full forward the throttle plates in the carbs are fully open and the motor throttles up smoothly through out the throttle range. If this is not the case, a link-n-sync will need to be done.

-- Jeff