Dinghy outboard maintenance done

A couple days ago I finally bit the bullet and replaced the outboard lubrication gear that had been stolen from my Saab last winter. I pulled the Honda off Buttercup, did the engine and lower unit oil changes and actually failed to hit the grease points because the brand new grease gun I bought from Boater's World isn't working -- no pressure? I should return that thing. In any case, I was shocked at the fact that both the engine and lower lube I replaced were practically new. Maybe I'm doing these oil changes too frequently?