This was the first year for this radical change to a solid engine design that had been used for years. The powerhead internals were mostly unchanged, but most of the external stuff was. The fragile side mounted starter is the achilles heel for these engines, be very careful when using it. Pull the rope slowly until the starter gear has engaged with the flywheel, then pull it to start the engine. Do not pull it out to far, and be very careful not to let go of the recoil grip..Releasing the grip usually will damage the recoil spring.
Yes, you should certainly pull the gearcase down and drain the lube. There is no need to replace the prop shaft/driveshaft seals unless there is evidence of water in the lube when drained. Inspect the aluminum impeller housing and SS impeller plate, then replace the impeller with the correct OEM piece. Lubing the driveshaft splines is extremely important, along with replacing the driveshaft oring. Use the OMC moly lube to grease up the drivehsaft splines, keep the lube off the top of the driveshaft. Failure to lube/seal these splines can result in premature spline wear which usually ruins the splines on the crank and driveshaft, expensive parts to replace for sure.
Yes, the magneto should be inspected, cracked/split coils will have to be replaced. The carburetor should be disassembled, cleaned and inspected. It is best to replace all the carb gaskets/float/inlet needle-seat using an OEM “carburetor kit”. Yes, replace the fuel lines and check the fuel filter inlet screen. Do not pull that fuel pump completely apart, you will be sorry if you do, just remove the black plastic inlet cover.
OMC recommended a 50:1 fuel/oil mix for this engine…But, I would recommend a heavier oil mix to protect the plain connecting rod bushing/bearings, consider mixing at 24:1 using a good quality TCW-3 outboard oil.
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