9.9 Mariner Lower Unit problem

[MH Hawker]

I have a 1996 9.9 Mariner ser. 0G119661. And it will jump out and back into gear if I give it to much throttle to fast. So far just cranking the friction lock down stops it, how ever I suspect it is a much deeper problem and I sure would like to find and fix it before it becomes a expensive problem. I got this motor used at the end of last year and it installed on a 20 ft pontoon. When I got it last year I changed out the water pump and I am beginning to suspect that the shift shaft measurement is off. Would this cause that sort of problem. The boat is presently on a slip but I am going to pull it off and bring it home to check the measurement. Any advice and comments would be apricated.

 

[MH Hawker]

Re: 9.9 Mariner Lower Unit problem

Well I got the boat home yesterday and tore into it and after I got the LU dropped off I did find a interesting measurement according to the manual the shift shaft in neutral is should be 22 inches on a long shaft motor nine was measuring 21 3/4 and the way the shaft moves it would make it 1/4 inch short on movement and the shaft cam could not be fully engaging the forward drive gear. Once I found that I stopped for the day deciding while I had it apart to go ahead and replace the water pump and seals. I spent most of the morning running around finding those and set in on it in the after noon. Wasn't bad other than keeping the water pump tube up and in place on this motor its a real poor set up. But its all about done and I will finish up tomorrow and depending on weather I may be able to splash it again and test run.

 

[MH Hawker]

Re: 9.9 Mariner Lower Unit problem

Finished it up today and drum tested it to make sure the water pump was right, I prefer a drum to make sure the pump is working instead of muffs. Muffs can force water up through the system even though the pump isn't working. should get it splashed tomorrow.

 

[MH Hawker]

Re: 9.9 Mariner Lower Unit problem

Got it splashed this evening and it seams to be working exactly like it should. No friction lock at all and it stayes in gear like it should. Hit it directly to WOT about 15 times.

 

[MH Hawker]

Re: 9.9 Mariner Lower Unit problem

Took 4 out riding today and it worked fine.