1991 55 HP two stroke Maintenance.

[deprim]

I just bought a boat with a 1991 55hp 2 stroke.
Runs great. The motor is new to me and I don't have a owners manual.
Is there any maintenance I need to do before I put it into service? Any oil to change. I notice two screws on the side of the lower unit. One says "oil level" and the other says "wash".
What are these for? Also what is the correct oil/fuel ratio I should mix?

[Ken]

deprim,
Not much maintenance on the two strokes. But here are some things to consider.
The worse thing you can do to the motor is let it set up for weeks at a time w/o being run. Try to run it at least once a week in the off season, even if it is just with the earmuffs and garden hose. If you let it set up w/o being run, you take a chance of the carbs getting clogged up with gum and varnish.
Run a detergent like SeaFoam or Yamaha RingFree in the fuel about every third tank to keep fuel system clean and carbon buildup at bay.
The fuel/oil ration is 50:1 - 12.5 gallons of gas to 1 quart of TCW-3 oil. Mix SeaFoam at a ratio of 1 oz to 1 gal of gas - not sure about RingFree, but instructions are on the can.
Replace spark plugs once a year.
You need to do a water pump repair about every three years.
You need to change the lower unit oil once a year per the owners manual. The drain plug is at the bottom of the lower unit, and the fill level plug is the one that says "oil level".
You would be wise to get the owner's and shop manual - go to www.yamahapubs.com to order online.
Good luck [img]smile.gif[/img] ,
Ken K

[deprim]

What is the "wash" screw for and is there a air filter on outboards?
Thanks for the information on the last post.

[Ken]

deprim,
I have no idea what the "wash" screw is for .
I have never seen an air filter on an outboard - only air "silencers" to minimize noise coming out of the air intake.
Good luck [img]smile.gif[/img] ,
Ken K