1963 mercury 1000 100hp 4 cly water pump change out

[godwjw01]

ive got a 1963 mercury 1000 100 hp 4 cyl im trying to change the water pump out but i cant get the lower unit off . i took off the bolt in the front then the two on top then the two the two on the bottom then the one ovove the zinc plate but it wont budge its in nuetral am i missing any thing????Please help!!!!

[Doug Redinger]

I have a 1963 850 Merc inline 6 cylinder that should be the same as yours if the year is correct. Although I thought in 1963 the Merc 1000 was also a inline 6 cylinder. I believe mine also had just the six bolts holding on the lower unit. The one in front on top, the two behind that on top, two on the underside of the ventilation plate, and finally the allen screw that holds the trim tab on. Although you might look up in the trim tab area to see if there is another bolt going up into the driveshaft housing. Its been a few years and I can't remember accuratelly. Corrosion may be holding the drive shaft, shift shaft or the water tube in place. Try shifting gears with the shift lever. Also try to slowly spin the motor over with the manual starter to see if it will jar loose the drive shaft from the powerhead. Just make sure the ignition is off. It's also a good idea to remove the propeller just in case. It might be alot easier if you get someone to help you. I use a rubber mallet to give the lower unit a whack.
I also use a heavy duty rubber bungee to hold the lower unit to the drive shaft housing so it doesn't drop off unexpectadly and break a housing or something. Good luck!!! If you do get it off remember to lubricate the splines on the driveshaft and the shift shaft before reassembly.

[Davesspeed]

I would be careful about hitting the cavitation plate with a rubber mallet, you could break part of it off. Try driving a thin gasket scraper between the gearcase and the exhaust housing about 2 inches from the rear. if it starts to seperate, work your way forward.
The stud that faces upwards in the front can get packed in with salt. If it seperates in the rear and seems to pivot in the front, the front stud could be packed in. More than once I had to cut through the exhaust housing to cut off the stud slightly above the gearcase to pry it loose. If you leave enough stud once the gearcase is removed you can use a torch and vise grips to remove the stud and replace it.

[chopo]

[QUOTE=Davesspeed;2047644] Try driving a thin gasket scraper between the gearcase and the exhaust housing about 2 inches from the rear. if it starts to seperate, work your way forward.


uh no, sorry Davesspeed. you should never ever drive anything between 2 machined surfaces. i dont know much about marine things but I do alot of auto work. I have seen alot of that done. and the fix was always large amounts of peratex junk. not a pretty fix and yes in does add some "meat" to your tolerances. just my 2 cents