Shift Cable, I think

[myoldboat2]

1974 Mercruiser 140 s/n 388xxxx
Mercruiser "Late Model I" Stern Drive s/n 390xxxx

Hello,

It's been 5 years to the month since I replaced the stern drive shift cable. Now I'm having this problem:

Sometimes when shifting into reverse, my single-lever control will go past the shift position and start throttling up the engine before it shifts the stern drive into reverse.

This started the last time we were out, and was happening maybe 1 out of 6 tries, but it seemed to be getting worse. Bad for the dogs, so I want to fix it.

I just started looking at it. Here is an animated gif showing the shift cable bracket motion:

Here are the three images:




Is this kind of rectangular thing the shift cutout switch lever? It seems kind of loose--with the shift lever in one position, I can grab the lever and move it fore/aft and up/down. Not sure if it just needs tightening or if the mounting on the shaft is wearing out.



I would appreciate your guys' thoughts on what I should look at next. I will disconnect the power and have my son hold the prop to check for engagement while shifting, and watching the cable bracket motion.

Thanks.

 

[myoldboat2]

Re: Shift Cable, I think

One more thing. I'm adding another post about a problem with the power trim system. In a nutshell: sometimes sterndrive started pulling up while in reverse, brought boat home on trailer, now weeks later, when we took the support strap off the sterndrive it dropped down, then trim pump wouldn't "grab" (just ran), went to add fluid and found oil on bottom of bilge (not engine oil).

Now I see in the power trim system diagram that there is a "reverse lock valve" that looks suspiciously like what I thought was the shift cutout switch lever (which is it?). So I thought I should mention this here--maybe this is all one problem?

Thanks.

 

[Bt Doctur]

Re: Shift Cable, I think

the reverse lockout is just below the arm thats moving,the shift interupter is not working either ,the arm on the right is moving too far.

 

[myoldboat2]

Re: Shift Cable, I think

What would be the next thing to look at to find out why the reverse shift sometimes needs lots of control lever travel?

Thanks.

 

[myoldboat2]

Re: Shift Cable, I think

Thanks for that advice, Bt Doctur. I read the Mercruiser manual over and over and went out to do all the cable adjustments. When I had both cables off, I crawled back there and had a good look at the shift cutout switch lever. It was riding forward of the cutout switch. The lock nut holding it had not moved, but the stud that the shift cutout switch lever pivots on had loosened from the bracket on the transom. Now I have it in place and moving correctly.

I went through all of the cable adjustments per the manual. I was able to set the adjustable stud on the shift lever all the way down and have everything work correctly so far (engine off, out of water). The prop engages fully in both forward and reverse at the right "throw" in the remote shift control. The shift cutout switch is centered in the detent on the lever at the times when the manual told me to check. The reverse lockout switch looks pretty good on the little markers lining up--it could maybe go another half a mark, but we'll see if the sterndrive pulls up when in reverse (how does this work, btw?).

I won't really know if the shifting problem is fixed until I get it on the water for a while. The problem was intermittent. I'm not really sure what I adjusted that could have fixed the problem I was having--maybe the shift cutout switch lever being so very loose, I don't know.

Thanks.