Most Snowmobiles have 2 stroke engines. 2 stroke engines require that oil be mixed in with the gas they burn. That oil can be mixed in before the gas goes into the tank or later on right before the gas goes into the engine. Adding oil to the gas before the tank is called premix, adding oil at the engine is oil injection.
The thing I think few snowmobilers understand is why they're adding that oil. Oh sure they know that if they don't add it their sled's motor won't last very long but what does the oil do and how does it do it?

That oil provides lubrication and helps the metal dissapate heat. It also ends up getting burned which causes the famous "two stroke smoke" and is a big reason why two stroke motors are considered dirty and bad for the environment.

So what does that mean? The average snowmobile owner dumps in oil and never thinks about it again, and for somebody with oil injection thats probably fine. If all your sleds have oil injection stop reading now, this article is about premix.
So you've got a premix sled, how much oil should you be putting in your gas? That totally depends on many factors:
Factor 1. What did the manufacturer specify for the sle
Factor 2. What oil are you using?
Thats right, depending on what oil you're going to use I'm here to tell you its perfectly okay to use way less oil than your sled manufacturer told you to.
DISCLAIMER - I'm taking no responsibility for your sled, messing around with less oil is a good way to ruin a sled motor. Think carefully about everything you do and then think some more. I've burned down a perfectly good motor in a moment of weak thought.

So my disclaimer has made you nervous, what should you do? Go out an buy some good quality oil and run it at the manufacturer's recommended rate.
What constitutes good oil? I'm talking about oil from a good upstanding manufacturer, Ski-Doo, Arctic Cat, Polaris and Yamaha all sell good oils. Klotz is good oil and Amsoil sells excellent oil. There are others and if you've got a favorite I didn't list drop me an email and tell me all about it. My rule of thumb, if you're buying your oil at Wal-Mart, KMart, the Dollar Store or any other cut rate place its probably not good oil. Sure you can use cheap oil if you run more of it but then you'll be fouling plugs and your sled will probably run like garbage. What fun is that? More importantly how much are you saving? The last couple gallons of Arctic Cat oil I've bought were $20 a gallon, there are 4 quarts in a gallon so thats $5 a quart. The cheap oil is probably $3 a quart but a set of plugs is at least $5 so by using cheap oil you're out $3.

If you're interested in using less oil go over to Amsoil's website and check out their 100:1 oil. This stuff is pretty amazing, they claim that any two stroke engine can run their oil at 100:1. I've personally run it at 60:1 in a '71 Ski-Doo Olympique 335 that normally would want 20:1 with no problems. The only problem I have is that the stuff is $8.50 a quart.
I did have to make a major carb adjustment to get the sled running correctly, the carb had to be leaned way down or it would coat the plug and the sled wouldn't run.

Okay so there were no problems running the Amsoil. The problem came later, I'd only mixed up a gallon so I ran out pretty quickly. My sled was way back in the woods and all I had hanging around was some 50:1 premix I'd made up for another sled using SpectroSno. As far as snowmobile oil goes I consider Spectro's regular blend to be pretty mediocre stuff, not terrible but nothing outstanding.

Anyway I put a couple gallons of that mix into the 335 and it got me home. What I should have done at that point was add oil to bring the overall mixture somewhere close to 20:1 since I was using just conventional oil, but I had heard that even beyond Amsoil's 100:1 magic oil that all conventional oils today are better than those of yesteryear and I thought that maybe the 50:1 would be okay. Remember I'd leaned the carb out.
The next time we went to ride I had a very hard time getting the 335 to run, I was surprised in fact how hard a time. I finally got it going and we hit the trail, before long I heard a noise that sounded like someone was tapping the clutch and pretty soon I was adding more throttle but the sled was slowing down. When I came off throttle the sled stopped DEAD and backfired out the carb. UH OH.

You guessed it, lack of lubrication, I kept pulling the engine over as it cooled so it wouldn't sieze but the damage was done, the rings had melted to the piston and the cylinder was horribly scored, after the engine cooled off there was essentially no compression. I wish I'd mixed up more of the Amsoil, I'm still curious how it would have fared.

As I write this I'm doubly curious, I've still got most of a quart of the Amsoil oil left but I'm not daring enough to try it in a sled I actually like. I think the answer here is a FRANKENSLED!
Yeah thats it a real rise from the dead machine worthy of the Dead Sled Wrenchers. Stay turned sledfans, this could be cool!