2-stroke Oil "Shelf Life"

So I picked up an 18 year old snowmobile that has 75 original miles – never even broke in. 130/131 PSI in the cylinders and had good spark but no fuel. It had maybe 2 gallons of fuel in the tank but the oil reservoir was plump full. The guy I bought it from said he put in enough gas to get it running and topped off the oil res.

I flushed the fuel tank, replaced [what was left of] the fuel lines, cleaned carbs, and got it running. I drove it about a half mile around my yard and it runs perfect.

The thought that just dawned on me is that the oil in the reservoir is 18 years old! It visually looks fine but am I asking for trouble using this stuff? If I need to replace the oil, how do I even go about that? Pumping it won’t get everything so do I remove the res and flush it out?

The way I understand it is that oil “can” gain moisture, but In your case of a tank Im not too sure. Its cheap insurance to suck it out and spend the ~$10 to replace it.

What I would actually be most concerned of is the lack of oil being on the internal parts for so long. Some say it is worse to let an engine sit for years than it is to run it. IMHO there is truth behind that. I would recommend adding oil to the first and maybe second tank just to provide a bit extra lubrication to the engine. Maybe 80 to 1 or so just to give a bit extra oil.

It is my understanding oil doesn’t age when sealed. However given the cream puff status of your nearly vintage sled I would replace it.

suzuki wrote:

It is my understanding oil doesn’t age when sealed. However given the cream puff status of your nearly vintage sled I would replace it.

Cream Puff?!?! Must be because the engine literally has your screen name stamped on it.

I would drain and replace. A few years back I was given the task of pulling down my dads two Yamaha Sno-scoots and get them running to sell. Both had been sitting for about 15 years on a rack in his garage and both oil AND fuel tanks were full…I removed the tanks and physically scrubbed them clean and topped them off with new. I wouldn’t risk the chance of contaminants in the oil tank plugging the injectors causing the engine to seize. You cleaned the carbs to keep the engine from melting down from a plugged jet, so why not clean the oil system too.

tswoboda wrote:

<div class=”d4p-bbt-quote-title”>suzuki wrote:</div>
It is my understanding oil doesn’t age when sealed. However given the cream puff status of your nearly vintage sled I would replace it.

Cream Puff?!?! Must be because the engine literally has your screen name stamped on it.

So now we know it’s a Suzuki motor. I don’t care what you do with the oil, I would like the back story on the sled. What brand is it, where and how did you find it? It must be immaculate with that few miles.

As always, photos are required.

Dutchboy wrote:

What brand is it,

It should be an Arctic Cat if it’s got a zuki motor in it.

404 ERROR wrote:

You cleaned the carbs to keep the engine from melting down from a plugged jet, so why not clean the oil system too.

You’re logic is solid, but I’m gonna go ahead and answer you’re rhetorical question anyway… The reason is because I’m scared. Cleaning/replacing the fuel system was easy and I’ve done it before. Oil injection is a little more intimidating to me since I’ve never touched it. If I mess up the fuel system, I’ll know because it isn’t running right. If I mess up the oil injection, I’ll know because the motor seized.

Dutchboy wrote:

So now we know it’s a Suzuki motor. I don’t care what you do with the oil, I would like the back story on the sled. What brand is it, where and how did you find it? It must be immaculate with that few miles.

As always, photos are required.

Sorry but all I got for you is a story with no photos…

2000 Bearcat 440 II – a class of snowmobile that really doesn’t have a lot of used stock. Fan cooled, cheap, decent mpg, cheap, relatively lightweight, cheap, and a giant track. Been looking for one of these or a Skandic 440 LT for many years.

A guy up in Orr, MN posted it on CList on a Tuesday so after work I hopped in the truck. I got to his trailer out in the woods around 9:00, looked the sled over, gave him $1,250 cash, and he loaded on my trailer using the forks on his tractor. Made it back home before 2:00 AM and to work the next morning by 7.

Well done. Enjoy your find!