[thedukeryan]

I just purchased a little 16' 1974 Del Magic with a Mercury 85hp out board. I have never owned a outboard before. The questions I have are as follows. What ratio do I need to mix the gas. The guy I purchased it from said he put one bottle in per 5 gallon tank. Next question. The boat is a trihull. From my understanding is that trihulls take turns better than a V hull but ride rougher. Can anyone briefly explain the advantages/disadvantages of a tri hull? Last question is at what rpm range should I be looking for while in the water and roughly how fast will 85hp push a 16' boat?

[83Evinrude]

Originally Posted by thedukeryan

What ratio do I need to mix the gas. Can anyone briefly explain the advantages/disadvantages of a tri hull? Last question is at what rpm range should I be looking for while in the water

I would guess 50:1 which would be a pint for each 6 gallons of fuel. Generally speaking a tri hull has more lateral stability but will ride rougher. I'm guessing your maximum rpm (light load @ WOT) should be around 5000-5500rpm.

I would visit the Mercury website and see if you can get a manual for your motor, then you will know for sure how much oil to use and what your max rpm should be.