Question on engine maintenance

[BruceB]

Hi Guys - I have a 2 year old Yamaha 4 stroke on my boat that gets very little use (30 hours since new). I use it year round but keep it at Clear Lake and don't make long runs. It's kept garaged and winters aren't harsh. My question is how often I should be changing the oil (engine and lower end) given how few hours are put on it - does it really need to be changed annually? As long as I'm asking, any other tips on maintaining it would be appreciated. Thanks!

[Ken C.]

I would recommend - as I'm sure the mfr. does - that you change the top and bottom end oils once each year regardless of hours. The problem is moisture contaminating the oil. Isn't the $50 bucks a year (if you do it yourself) worth it? I think the four strokes have a timing belt that needs to be inspected and tension checked every once in awhile. Don't forget fuel filters! (You should have a water seperator inline also!)

[Hipster]

Everything Ken said plus check the prop for any line wrap etc. make sure the motor gets all the way trimmed down in the winter to remove any excess water in the lower unit to protect from freezing. A boat or vehicle just sitting can be worse than a over used boat or vehicle motor!!

[FRANK D. LOZANO]

Hey Bruce,
The only other thing that I would add would be to treat your fuel, add it to the tank and run the motor to get it the fuel system ie: carbs or fuel injectors.

Carbureted 4 stroke units are notorious for varnishing up with old fuel. They have 1 carb per cylinder and meter very small amounts of fuel, and as a result have small orifices in the jets.

This holds true to everyone with a boat that may be sitting any length of time. With the ethanols and additives in today’s fuels it is important to treat it or use it. As a matter of fact, Mercury says that’s fuels loose their aromatics in as little as 15 days.
Aromatics are the components (light vapors) in gasoline that enable them to start cold. You know, like the bubble, pop, fizz in 7up that goes flat overnight.

Good Luck

[Terry Smith]

This web site has A lot of info on your Four Stroke motors maintenance.




www.knapiksmarine.com/2070.wmv

[spanky99]

I know my four stroke dirt bikes have break in oil that supposed to be changed after 10 hours of use. Is this the same on four stoke outboards?