Re: gear oil and water pump
You have to separate the lower unit from the mid unit. if you have a 5 inch spacer on the leg to make it a long shaft engine I think you separate the lower 4 bolts. then put the engine in gear-- I forget which gives you the room, it might be reverse, but you will see, and spread the lower unit apart from the mid unit. Reach in at an angle with a screwdriver or allen wrench depending on the kind of screw, and unscrew the screw holding the upper and lower shift rods together. Now remove the lower unit. Sometimes on these old small motors, the drive shaft will be stuck in the crankshaft If you force the leg apart, the shaft will come out of the pump and the drive pin for the impeller will ruin the upper seal on the water pump, and will bend, but don't worry, these parts are standard and still available as is the impeller. the shaft is splined on both ends so no other damage will be done by pulling it out of the water pump. To get the shaft out of the crankshaft, spray liberally with WD40 and use some sort of impact puller on it. If the shaft is not stuck, the lower unit will come right off. You will see the water pump held on by three or four screws. remove them and you can now replace the impeller. When you reassemble, be sure that the brass water pipe re enters the white plastic collar on the pump body. That impeller was used on just about every 8, 9.9, 10, 12.9, and 15 hp engine. it is fairly cheap and easily available at any Mercury dealer.
