Re: 1975 9.9 Johnson outboard
Where I live, that is about what they go for. They are a good motor, will run for years, but as Rick said and like all other motors a little maintenance is required and will be ongoing.
If you can check the spark and get it to jump a 3/8" gap, I would probably not replace any coils, points, condensers or wire unless another problem came up that forces you to do so. It wouldn't hurt to re-set the points gap but if it runs well and you have never done that before, I would waive that as well.
I wouldn't install a new tell tale since, I personally have no problem viewing the water from the exhaust port, as per that model's design, so I do not know why people go to this trouble. Even the carb kit. If it starts, runs and most importantly idles well, I would leave that as well.
The impeller needs to be changed, even if it pumps water well, unless you know how old it is and it is less then 5 years old. Impellers need to be changed when they are working well, since the alternative is to wait to change them after they fail. That plan only gives you, at most, a 60 second window, so change the impeller, its a $15 part and a 1 hour job.
The gear oil also needs to be changed every season if left below freezing temperatures in the winter and fairly regularly, even if stored in your basement. Look to see if water is getting in. The oil will be a milky consistency and if the motor has sat for more then a week, the water should be at the bottom of the mix and come out first when you open the drain screw. If no water, yell "yeah baby", and re-fill it with gear oil.
