Perhaps I can add a few tips to Sam2001's excellent advice. Over my lifetime of 75 years, I have spray painted a number of cars to include an antique Mercedes and two sports cars, and learned some lessons along the way. I applied them to painting my 1991 25HP a couple of years ago. Based on what I read on this forum, I used a high quality acrylic urethane automotive paint. I have also used Imron single stage paint on boats in the past with success. Here's some tips for consideration:
Avoid the spray cans, too hard to apply smoothly without erratic drops/drips, low quality, not hard enough, and uneven overlap. Use a high quality sprayer and compressor setup. You can even use a Harbor Freight sprayer and just throw it away if you hate doing the cleanup afterward. Hint: it takes forever to disassemble and clean the gun with the reducer.
Preparation is the key to a great result. For the hard to remove remaining paint on the cowling, I used Kleen Prep aircraft paint remover and did the stripping and sanding of the cowling on my workbench.
If the paint on the rest of the outboard is intact, lightly sand and/or use a deglosser for best adhesion before priming.
Because I had some bare metal spots, I used a self-etching primer and applied enough coats to be able to sand smooth.
You will still end up with some pinholes, I used DFL17 Red Cap red oxide spot putty to fill them and resanded lightly.
For the blue topcoat, I used a high quality automotive paint, Shop Line JAU#1, Direct Gloss acrylic urethane. Paint shop mixed exact 1991 Evinrude blue metallic color for me.
You will need reducer, I used Shop Line JR506, to thin the topcoat based on temperature and add a medium topcoat hardener, I used Shop Line JH6680. The specification sheet that comes with the paint will tell you how much.
I masked everything meticulously and applied thin coats to avoid orange peel.
I did not buy the decals because I would have had to apply a clear coat over them. Since you have already bought them, be prepared to buy the clear topcoat and more hardener and do this extra step. Don't be surprised if they start to peel off in a number of years of constant sun exposure.
Good luck with the job, take your time during the offseason and you will be pleased with the outcome.
