This is my first outboard and I don't know how to use it yet. I've ordered the manual but until it gets here, I could use some pointers. I'm having trouble getting it started. It's extremely hard to pull the cord. It's much harder to pull than any other pull-start engine I've used in the past. I've got it primed with a 50:1 fuel mix and the throttle is set to 'start'. Is it normal for a motor of this age or am I doing something wrong? This is a 1972 Evinrude 25hp and it was sold to me in running condition.