Engine Suddenly revved and speed dropped, then recovered

[peters715]

1969/70 Mercruiser 120 A1G1.

I was cruising along downstream around 3k RPM when the engine suddenly revved up quite high and speed dropped. I immediately pulled the throttle back to forward detent. Checked gauges and quick look under doghouse and nothing was amiss.

Throtttled back up to 2000 and cruised down stream through no wake zone then opened up briefly to 3500 without any issues.

Got to the dock and shut down to get the trailer. Started the boat back up and no forward gear. Had reverse but no forward.

When I got home and pulled the cable end off the cable and found the cable end became 'untwisted'. I'm reasonable sure this is why I lost forward gear as the cable was collapsing rather than pushing.

This era of shifting cable uses twisted cabling. Is is possible to substitute solid core wire instead?

Also, could this explain the sudden engine rev while under load? I can't imagine this could but I am at a loss of what else it could be.

 

[redneck joe]

I am by no means the person to help you but what does untwisted mean

 

[peters715]

I am by no means the person to help you but what does untwisted mean

Fair enough. I didn't have a pic at the time but now I do.

 

[redneck joe]

Ah, braided of sorts now not. Interesting to follow this thread.

 

[matt167]

Your shift cable probably isn’t holding position like it should. So you get it to pop out of gear and yes if it is no longer structural so to speak. Your cable is spinning on the other end

 

[dwco5051]

Putting the cable in compression rather than tension might cause it to look like that. If something banged against the end. A real mystery to me as to why it happened.