Tohatsu m90a lower unit

[9ernate]

Hello all I am new to this site and to all forums as well but I would like to ask a question to those of you with a lot of knowledge as I have a read. I have a 1996 Tohatsu m90a with a bad lower unit and I have not been able to locate one at least not at 96 lower end. My question is will any other lower units lineup and work with the 96 m90a. I should have asked other years or Hps

 

[pvanv]

What is wrong with your LU? Bad gears? Seals? The 90A was made from the early 90s through about 2000. Plenty of used stuff out there.

 

[9ernate]

Well I’m embarrassed to say that I’m the one that messed it up. I noticed that it was not peeing water like it should’ve been so I knew something was up and I pulled the lower unit off and the bolts holding the water pump cover down we’re pretty much frozen from salt water. So everyone of them snapped off. when I tried to drill them out and I did not do a good job and all the holes got way too big. I basically ruined the the area to bolt the water pump body to.
anyway I don’t really feel like paying $600 for just the lower end assembly when I can find one used for like 750 but I can’t find one for the exact year and Hp. Help

 

[pvanv]

Year is irrelevant. As long as it's for a 90A, it is the correct one.
A decent machine shop can probably fix your oversized holes... either with helicoils, or weld shut and re-drill/tap. Install the new bolts with antiseize compound so the come out next time.
FWIW, poor peeing in not necessarily an overheat indicator. Crud in the pee tube can cause that, while cooling is still OK.

 

[9ernate]

Thank you Paul. I think the idea of fixing mine thru a machine shop is a great one. I will pursue that. Thanks for advice on water cooling. When I finally did get water pump cover off the impeller was shredded and parts of it were plugging flow. Looks like no had ever changed impeller. I will post after repair

 

[9ernate]

Here’s an update. I went to several reputable machine shops today brought the low-end with me. The only one that was willing to attempt to repair said I would probably be better off just buying a used one because it would probably cost five to $600 for the repair work. So I pulled the unforgivable sin and made the low-end a one and done. I eproxied the base of the water pump to the body and then the water pump cover to the base so it will either work or the low-end is junk. I will know tomorrow when I fire up the motor and run water through it to see if it’s going to pump water.