I just acquired a 1990 Mercury 40 hp outboard motor. The motor is beautiful and runs wonderful. All of the regular service has been updated. My question is what oil is recommended in the oil injection system of this motor. This is not a fuel injected engine, just an oil-injected engine. I am curious of my options and your personal recommendations. I want to keep this motor running well for many years. Thank you in advance for your suggestions.

