Marine PRO in a Mercury 4 stroke 90hp outboard motor [SOLVED] Asked by Charles R. In South Dakota How do I use Marine PRO in a Mercury 4 stroke 90hp outboard motor?
Hi Charles. I would add Marine PRO to every tank of boat fuel. Marine PRO cleans fuel passageways, lubricates, stabilizes fuel, and provides corrosion protection to upper engine areas. At least two times a year I like to add a can or two a low tank of fuel and run the engine under load (hole shots, high RPM).
This video covers the high cleaning concentration idea: