Do you replace your 2-stroke oil every year?

[capslock118]

Hi everyone,

I'm debating this for myself. This past year I replaced all the oil left in the reservoir because I hadnt done so since I bought my used boat 2 years ago.

Now I'm wondering if I should do so every year?

My engine is 20 years old, 135hp 2-stroke blackmax, so I figure that I am going to start using a better brand than..well..store brand oil.

I guess I am assuming it's like a car, My truck is from 95 and I use high milage oil because it is said this oil has additives that help keep the seals in good shape. I figure they must have this for marine engines and I figure, like a car, you want to change your oil regularly. Might be more expensive than store-brand but if those extra addatives work then it's still cheaper than worrying about things taking a turn for the worse.

that said, do you change over your oil annually? sooner than that?

Do you change over just the oil in the reservoir, or do you also change over the oil you find in that primary compartment found above the engine?

 

[robert graham]

Re: Do you replace your 2-stroke oil every year?

I doubt that oil has deteriorated any but if it makes you feel better about it, then dump it and put in fresh oil.

 

[capslock118]

Re: Do you replace your 2-stroke oil every year?

I doubt that oil has deteriorated any but if it makes you feel better about it, then dump it and put in fresh oil.

I guess that is what I am asking - does it deteriorate over the winter? It wouldnt make me feel better spending $60 - $100 on oil if there is no need to replace it. It would make me feel better replacing it if that is what ought to happen.

Like I was stipulating, an american cars oil is replaced every 5 months / 5,000 miles at most - while manufactures typically recommend 3 months / 3,000 miles.

Does this line of logic not carry over on boats or does it? The boat is just sitting on land during late fall / winter / and early spring. So about 6 or 7 months out of the year the oil will just sit there. Does that hurt the oil? does it matter?

Actually in the two to three years i've owned the boat I've never run out of oil. I replaced and put two gallons in this past spring and maybe 1 gallon has been used this year. So, that means that, untouched, a good portion of the oil would not be used for at least a year and a half.

Is that expected for the life of the oil?

 

[Chris1956]

Re: Do you replace your 2-stroke oil every year?

That oil will last years. I would fill the resevoir at layup and leave it alone. A good idea is to siphon some oil off the bottom of the tank, in the spring. Any water that has condensed will be under the oil, and you can get it out.

 

[j_martin]

Re: Do you replace your 2-stroke oil every year?

There shouldn't be any water in the oil tank unless you leave the cap loose, or get some in it when filling it. If you are careful and clean filling it, just leave it. It'll be fine.

When I first got my boat, I dumped the oil out of the boat tank and ran it through a paint filter, to get the spare parts, leaves, oil bottle seals, etc out of it. Then dumped it back in.

You can change oils by adding oil. They should mix OK. Or you can run the boat tank completely out, setting off the alarm, and then fill it from there. Just crack the cap on the engine tank till it overflows to re-fill it.

hope it helps
john

 

[mc66]

Re: Do you replace your 2-stroke oil every year?

never . own 4 2 strokes just fill to top before storage leaving no room for condensation

 

[8hygro]

Re: Do you replace your 2-stroke oil every year?

U.V. light and heat would cause degradation of the oil. Use your judgment if you feel those extremes were present. As others noted...an occasional mixing and dillution of any old product should be sufficient.

A "drip test" would be a down and dirty method for comparison to fresh oil. You would be loooking for gelling or thickening. Hmmm....reminds me of bean oil's!

8hygro