Water Pump

hallsgates

Cadet
Joined
Mar 21, 2007
Messages
7
Can anyone tell me how to replace impeller on 1973 Merc. 3 cycl. 65hp. Mod. 650. How difficult is it. Have a general idea but need instruction. Thanks Larry
 

jebeebe

Petty Officer 1st Class
Joined
Nov 26, 2006
Messages
322
Re: Water Pump

You should have a manual, but here goes. Remove the little plastic cap on top the cavitation houseing. There is a bolt down inside the hole that holds the trim tab on. take off the tab and under it is a nut that holds the lower unit on. There is also another nut near there but not under the tab. There should be two nuts on the side near the front of the lower unit. With all these removed the lower unit should come off. put the shift lever in neutral.

When you get the lower unit loose, you will lower it and the water tube(copper pipe) and the driveshaft will come out with the lower unit. When reinstalling the copper pipe can be put in the lower leg first then hooked up at the bottom where you can see what you are doing.

After you have the lower unit off, remove the rubber seals from the driveshaft end (pay attention to how they go on) and slide the rubber gasket from the pump up the shaft and off. Remove the three nuts from the top half of the pump and pry off the upper half of the pump. Slide the upper half of the pump up the driveshaft and off. Be sure not to loose the little key from under the impeller. When installing the new impeller, lube the houseing with vassolene and turn the drive shaft clockwise as you shove down on the pump houseing. This will get the new impeller started in the right direction.
bolt the houseing up and reinstall the rubber gasket and upper seals.
Slide the lower unit up in place or until it stops about an inch frome home and hook up water tube and aligh driveshaft.(may have to turn flywheel to get the splines to line up.) Make sure shift rod couples to shift shaft and it should slide up tight..............Jerry
 

gejandsons

Petty Officer 2nd Class
Joined
Sep 11, 2003
Messages
134
Re: Water Pump

If you leave the shifter in gear when removing the lower unit, you can turn the prop to realign the drive shaft during reassembly.
 

hallsgates

Cadet
Joined
Mar 21, 2007
Messages
7
Re: Water Pump

Thanks for the info, I know I need a manual but have'nt been able to find one yet. Will try installation today, maybe on the lake tommorrow? Thanks again.
 

hallsgates

Cadet
Joined
Mar 21, 2007
Messages
7
Re: Water Pump

Thanks guy's, installed water pump today using your instructions. Could'nt have went better. Tell tale squirts about 3ft. constant stream with muffs and garden hose on . I Will be on lake tommorrow. Any idea's on where to look for a manual for this motor. Thanks Larry
 
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