1976 Merc 850 parts

[72mtwain]

I bought this boat in late fall, motor hasn't been ran in a while, don't know how long, at least a year, probably longer. It starts and sounds good, decent pee stream. I figured since its been sitting I will change impeller and would like to change the seals while lower unit is off.
I want to get a parts list together so I can order and have them here, problem is I Boats doesn't list my motor in the parts look up. Can anyone reccomened what parts to replace and where to get them? like I said, merc 850 serial # 4368861. any help much appreciated.. thanks

 

[carholme]

Re: 1976 Merc 850 parts

Twain;

This covers the 4 cylinder serial number range 4366802 thru 4831998.

http://www.crowleymarine.com/mercury-outboard/475.cfm

carholme

 

[72mtwain]

Re: 1976 Merc 850 parts

Thanks for the info. Any suggestions on what seals I would want to replace?

 

[carholme]

Re: 1976 Merc 850 parts

Twain;

You could order the driveshaft seals which fit under the waterpump base but I would wait until I had the LU off and drained the oil to see if there is any water in it. If it is good looking oil, you could always do a LU pressure check before changing the impeller. If the pressure holds, just change the impeller and gaskets. Some will advise changing every seal and gasket but with my 1968 Merc 500, I do a pressure check every year when the LU is removed and it is still running like a top, on it's 4th year since LU overhaul.

It all depends on your level of expertise and how much you want to tackle

carholme

 

[Chris1956]

Re: 1976 Merc 850 parts

If the gearcase seals are good, inspect the SS cup in the upper pump housing. If it is scratched up, replace it. Always replace impeller, wearplate and both gaskets above and below wearplate. If you need to replace driveshaft seal, replace pump base gasket and Oring as well. BTW- if you do have a waterleak, it is usually the driveshaft seal. In this case, just replace the pump base, gasket and oring.