6 year old 2-cycle oil

[RottenScummyTroll]

Question for you: does 2-stroke oil go bad over time?

Here's why I'm asking - I just picked up a '95 Summit 670 that hadn't run since 2003. Now, I emptied all the old gas out, cleaned carbs and it fired up on the first pull - sweet! But it smokes quite a lot even for a 2-smoke, so I'm wondering if I should change the old oil out or just run it?

 

[spomey]

no just run it, most likely it hasnt been completely warmed up/hot.

you have oil pooled in the cases that is causing the smoke or oil in the pipe and can or both. let it get warmed up real good before you spend extra time effort and money on it.

JMHO

Spomey

 

[skibreeze]

Run it.

 

[RottenScummyTroll]

Good point. I let it warm up a bit, but certainly not all the way. We'll take her out for a cruise this weekend and see how the old girl does...

 

[rockdog2112]

Question for you: does 2-stroke oil go bad over time?

Here's why I'm asking - I just picked up a '95 Summit 670 that hadn't run since 2003. Now, I emptied all the old gas out, cleaned carbs and it fired up on the first pull - sweet! But it smokes quite a lot even for a 2-smoke, so I'm wondering if I should change the old oil out or just run it?

First, all petroleum products break down over time. I would think six year old oil is questionable at best. Second, who knows how the original owner had the ratio set up on the oil injector. I agree with the others that you should run it untill it is at operating tempature and see how it is. I'm not a two stroke mechanic but I do work on my old Powder Specials and I would change the oil simply because it's part of the process of elimination when trying to solve a problem. If it still smokes, look elsewhere like plugs and injector. Just my two cents. Good luck.

 

[donbrown]

If oil is in question drain it and replace with new oil.

If the oil injection system is suspect add oil to the fuel and run it with oil in the fuel till you confirm the oil injection system is working.

Keep the old oil and mix it with new oil for the fuel mixture or use it for chainsaw chain oil or general lubricant for parts.

Use the old oil to coat metal as a temporary rust inhibitor.

 

[diggerdown]

Change it, acids grow in old oil and is hard on seals. Oil picks up moisture and that is hard on everything else in the engine.

 

[BigTruck]

Six year old oil???


Drain it!

 

[Dogmeat]

Question for you: does 2-stroke oil go bad over time?

Here's why I'm asking - I just picked up a '95 Summit 670 that hadn't run since 2003. Now, I emptied all the old gas out, cleaned carbs and it fired up on the first pull - sweet! But it smokes quite a lot even for a 2-smoke, so I'm wondering if I should change the old oil out or just run it?

Well, really, that oil was already probably 100 million years old before it ever got refined and put into that SkiDoo, so I wouldn't worry too much about it

 

[sodfarmer]

More than likely if it was mine I would just run it especially if it was stored indoors. If it was stored outdoors I would be a little more concerned about it.

Also I agree with spomey. There is alot of oil in the bottom of that case after 5 years. You just need to run it to clear the excess oil out.

Just my $.02

 

[coptzeer]

change it definetly!. at least drain it. check the inline filter if it has one and if it looks good run it through a paint strainer then, use it.. i wouldn't.....
bought a low milage well maintained xlt years ago. sat long enough that we lost a crank seal eventually. pulled the oil bucket with the engine and i was amazed at the condition of the oil...yuk! its cheap and eazy to change....

 

[ttyR2]

Change it. Oils do go bad after a period of time (iirc a lot of oil manufacturers say use within 2 years). The additives in the oil break down and aren't effective. Not to mention oil just isn't that expensive, why risk it?

 

[RottenScummyTroll]

Thanks for all the input guys. Upon further reflection, I decided to spend $5 and change it out - peace of mind and all that.

I'll take her out tomorrow and see how she goes in the mountains.

 

[wickman]

Well, really, that oil was already probably 100 million years old before it ever got refined and put into that SkiDoo, so I wouldn't worry too much about it

The base oil is not the problem, the additives will break down over time. An uncompounded oil has a shelf life of around 8 years and a compounded oil has a shelf life of 2 to 3 years. Will it still be good after that time? Probably, but isn't changing the oil cheaper and easier than a rebuild? Drain it and put new, or if it is low, top off with fresh.

 

[Killerk]

Interesting.
I am still running 7-8 year old oil in my 08 sled with no issues.
I have 10 more gallons... I'm not gonna throw it away. And I would never use it all in my weed eater.

 

[farmboy84]

i got the old mach 1 running last week. the last time it was registered was 2001 and i bet 40 miles were put on that year. the oil in the tank had to been at least 8-9 years old. it smoked a bunch at first but i put 120 miles on it last weekend with the family and she ran great.

 

[pernikm]

It depends how it is stored, sunlight can break down the long chain molecules. Nothing can hurt the zink antiscuff additives. Sunlight aside, the lubricity of the oil will not change. There are some drying agents in oil that aid in corrosion protection. Oil in itself does not attract moisture, but these additives absorb moisture inside the engine. I would worry about the motor sitting for 6 yrs. The additive package probably got tired in that time and you might have some internal corrosion. Running one tank of oil through probably does not matter much since the very next tank will refresh the additives. If I had 5 gallons in a non-sealed jug, I would probably throw it away since running an engine for an extended time without corrosion protection might be unwise.

Karl

 

[ttyR2]

Old oil won't necessarily cause an immediate engine burndown either, but it certainly doesn't lubricate as well as fresh oil would. You're taking extra time off the life of the engine.