I just got a quote for $225.00 to change my water pump. That sounds high to me. All that needs to be done is drop the lower unit and change the impeller right? On an 1982 40 HP Merc, do you have to change the grommet in the bottom of the power head too?

I've got a 1979 Mercury 40hp also, super easy to change impellers. I'd never pay $225 to let a mechanic do that job. The impeller is only 21 bucks if I remember right. If you were closer to College Station I'd come do it for you for free. You don't have to change any grommet in the power head. The only things that might need replacing are the seals around the base of the impeller housing. But if they look good, they are fine. I've never replaced mine and its never been an issue.

Thanks! I think I will go pick it back up and do it myself. I hate to get an estimate and the. Bail but I think I am getting charged to much on this.

Yeah man, for the simplicity of the job, thats a rip off. It takes me about 20 minutes to do the whole thing. The part that takes the longest is when you have to line up the impeller with the impeller key and press the fins of the impeller back so the housing will slide over the impeller. I just use a flat head screwdriver and gently push each fin back so the housing will fit. Also, I always use a dot of grease to hold the impeller key in place on the driveshaft while I slide the new impeller over it.

dont need to press impeller back in place with screwdriver all this will do is damage impeller...Put grease in houseing turn clockwise and its installed...

It doesn't hurt anything. You use the flat part of the FLAT head and gently press the impeller fin down. It does not take hardly any force. If you try to put the impeller in the housing before sliding the housing over the studs, you have to put the impeller in the housing and make the groove in the impeller line up PERFECTLY with the ridge on the impeller key, and that is harder to do than if you put the impeller over the key first, and then slide the housing over it. I've done that for every impeller I've ever owned and after a year of solid use, I replace each impeller regardless of whether or not it needs it, and I've never had one torn up or ruined. To each, his own. It always works for me.

And when the shift shaft jumps into the wrong place, what do you do? I agree that 225.00 is high but if something goes wrong during reassembly, it would sound really cheap.

On those motors, the shift shaft can be grabbed about 4 or 5 inches above the cavitation plate. As long as the shift arm and the lower unit are in the same gear, its not hard. You just hold the shift shaft with one hand, and line it up with the splines on the male end of the shift rod on the LU, and push it together. I knew nothing about outboards 6 months ago. I got my Craftsman set out and rebuilt everything except the powerhead because it didn't need a rebuild. These old merc's are not hard to work on. I'm not at all trying to sound arrogant, so please don't take it that way. But really, if you bolt the lower back up and try shifting it and the prop doesn't spin the correct way or it won't shift, you just pull it back off and grab the male end of the shift rod on the LU with some pliers (padded with a rag so you don't damage the splines). Then you just twist it so it matches the same position of the Shift arm on the control box. Trial and error. Besides, if you do it once, you save yourself $225 bucks every year, or however often you replace your impeller.

Really not that hard. Lots of videos on youtube. Basically the setup is the same for most motors. Should be a 1 hour job the first time. I would change it out every 2-3 years. Didn't change my initally out till 5 years cause I was lazy and the impeller looked new. Now, I'm gonna change it out every 2 years.

Yall do`nt understand, as far as I know Merc-Mariner is the only ones that on some of the 40-50&60hp outboards that have the shift dog in the prop shaft spring loaded. If the cam jumps past the gear position, it is a pain to get it back in right place. I remember first time I had this same thing happen. Pulling the lower unit out and you hear a pop from the shift shaft jumping. WOOPS Good Luck

I decided since the mechanic helped me trouble shoot another issue I was having it would be wrong to pull the whole rig home so I let him do some of the work I needed done, including the water pump. I still think it was a little high but I could not take his free advice and run. We all have to make a living. I will do it myself next time. Besides, I did not want to mess with it.