1994 Mariner 40 hp, 4 cyl shift problems

Hello all, I am in desperate need of advice on what to do. I bought my boat and motor last year and discovered I needed to change the bottom end seals. I dropped the bottom end, changed the seals and the impeller. I was in a rush to get it back together as winter was coming. This spring, I started up the motor with dogears on and everything seemed great, I had my gears and they switched beautifully. I dropped the boat in the water to get some fishing in and when I pushed my throttle forwards, the boat was in reverse. It was the same for reverse. I dropped the bottom end again and rotated the shift shaft opposite of what it was. When I put it back on, all I had was forwards. I dropped the bottom end again and tried lining up but with no different result. A friend and I took apart the propshaft and lined up everything, checked that there was movement of the cam and everything seemed great. Then we noticed the culprit. There is a ledge built into the intake manifold just below the lower carb that seems to hold the shaft down when stress is being put on it. This ledge has snapped and was lying there. The nut on the linkage was actually rubbing on the bowl of my lower carb. The shift shaft moved freely down into position. Is there a fix for this or do I have to replace the entire intake? A friend of mine has some Devcon putty that apparently dries really hard. I'm picking it up and trying it tomorrow. I'm also going to call a local marina and find out if their mechanic has any ideas. Anyone out there have any ideas that could help? Thank you for any and all ideas.

Re: 1994 Mariner 40 hp, 4 cyl shift problems

First of all, what is your engine s/n?

Gerry

Re: 1994 Mariner 40 hp, 4 cyl shift problems

My serial number is 0G083931. I am actually trying an epoxy on the lip that broke. I put it on today, 4 hours later I checked on it and it seemed pretty hard. My buddy had it from the mine he used to work in. I'm going to give it until tomorrow to install the lower end again. Then it's crossing my fingers. There is one person in town that'll weld white metal, but I'm going to try this to see if I can get through this year. I'm still open to any suggestions too.

Re: 1994 Mariner 40 hp, 4 cyl shift problems

Your s/n comes up as:

MARINER - ( 40 H.P. (1994 ))
Serial No: 0G083931 Model No: 7040412CT

Parts List for model 7040412CT:

40 HP30 JET - Mercury, Mercruiser, Force, etc. Parts Lookup

This link from the parts list shows the upper shift shaft. Does this show the area you are referring to?

Mercury, Mercruiser, Force, etc. - ADAPTOR PLATE/SHIFT SHAFT - 40 HP30 JET

Gerry

Re: 1994 Mariner 40 hp, 4 cyl shift problems

That is my motor. The shift assembly is the right one, but what I'm talking about is on the crankcase and cylinder block assembly page. In the diagram, beside #10 stud you'll see something like a nose directly below the bottom carb intake. That's the piece that broke. I tried putting my bottom end back on yesterday with the putty in place. It didn't hold but it did create a wedge that keeps the shift shaft in place as I now have all my gears back. Took it on the water today and it shifted really smooth. I know it's only temporary, so I hope it lasts a bit. Still looking for advice on a long term fix.