RZ350 - Removing the Oil and Water Pumps
Both the oil pump and the water pump are located on the right hand side engine side casing. They run off the primary drive and are accessed by removing a plastic cover retained by three bolts.
The Phillips head bolts can be a little stubborn so using an impact driver is a good idea. When they are replaced it is a good idea to find an allen head alternative to make future removals more easy.
The water pump is the upper of the two assemblies and is covered by a flat galvanized metal plate. The oil pump is located below. The oil pump in the motor I disassembled had been disconnected from the oil tank. Also the two oil feed lines to the carb had been connected to each other to form a loop so a working oil pump will have different connections.
Turn the throttle wheel on the oil pump and disconnect the throttle cable before the pump is removed.
The oil pump is held in place by two Phillips head screws. Once they are removed the oil pump can be removed. There is also a small gasket between the casing and the pump which should be renewed. The drive shaft will be left in the casing.
To remove the oil pump drive shaft the casing needs to be flipped over. A plastic drive gear is held on the shaft with a retaining ring but no washer. Remove the retaining clip and remove the plastic gear.
The gear spins with the shaft due to a small dowel through the drive shaft which fits in a slot in the gear underside. Push the dowel through the shaft and keep it in a safe place for the rebuild. The shaft can now be pushed through the casing and the remaining oil seal can be pried out and replaced during the rebuild.
The water pump plate is held in place with five Phillips head screws which were a real pain to take out. Even the impact driver wouldn't turn them so I resorted to vise grips to remove them. I plan to replace these with stainless steel allen head bolts so I didn't mind destroying them during removal.
Take the water pump cover off to see the impeller inside. The gasket on mine had turned to a solid mess so I removed it with adhesive remover ready for the new gasket.
The pump is driven by the primary drive through a plastic gear on a drive shaft. Flip the casing over and you'll see the pump drive. The gear is held on the shaft by a clip and washer.
The same idea of a dowel through the shaft is used on the water pump as well. Remove the dowel and the impellor and shaft can be pushed through the casing..
This water pump needs a good cleaning before being put back together. Luckily the shaft is in great condition.
Finally the bearing and oil seal can be removed from the casing. The bearing on this one just fell out but it is always possible to drive both the seal and the bearing out from the other side of the casing with a small socket.
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