Motor Question

  I got a 50 hp Mariner tiller, I believe its a 1999.  I've always winterized and stored it in the garage in winters and never had a problem. This year I had it out and it was running great like it always had. We were heading in when the motor just shut down, I mean it stopped so hard it threw my brother and I to the floor. We restarted the motor and we could put it in forward and it would work but as soon as I gave it any throttle it would start to shake and then shut down hard again.  I drained to lower unit oil to see how bad the damage was and surprisingly it wasn't bad, so I refilled it and put the muffs on and it started fine, in neutral it will throttle it all the way open, so I put it in gear and throttled up and it got wide open without a problem. So I took it out to a small local lake and as soon as I started to throttled up it did it again. Does this sound like a blown lower unit or something else? My local boat shop  says its 150$ just to look at it. Any input would be appreciated.

 Sheared gears. That's why it would run fine with the muffs and went to pot with load on it.

A wide human, any update on your motor yet?

I kinda had a problem like that. Only i have a 90hp 4 stroke efi.  Felt like one or two cylinders were shutting down as soon as u put a load on it on the lake. Still did it in the driveway but not as bad since it wasnt pushing much of a load.  Ended up being the fuel regulator was stuck open and causing my engine to make oil.  Really could be a couple of things.  We went thru the whole fuel delivery system, to spark plugs, to coils, before we finally found the problem

Thats a tough one.  Is the motor shutting down as in stopping running, or does the prop shaft stop spinning.