2 Stroke Engine Oil - What's the best 2 stroke engine oil?
When it comes to the question, what's the best 2 stroke engine oil, everyone, and I mean everyone has an opinion. The truth is there are many great 2 stroke engine oils available on the market today.
First of all, if we are talking motorcycles here, we use 2 stroke engine oil for our premix or oil injection systems, but we are also using a different oil in the clutch/transmission of our 2 stroke engine. This article is focusing the on premix and injection type.
The purpose of 2 stroke oil is to lubricate the bearings on the ends of the crankshaft, the connecting rod bearings, and the cylinder walls. The mixture (fuel,oil,air) flow through the intake track into the crankshaft area and the cylinder. The oil in the mixture tends to coat everying with a constant fresh film of 2 stroke engine oil. Often when you start a cold 2 stroke you will see an abundace of smoke. This is typically due to excess 2 stroke engine oil which has "settled" in the bottom of the crank shaft area as the fuel evaporated away while the engine was sitting.
There are basically 3 types of 2 stroke engine oil available:
- Petroleum based oil (or "dino" oil, refering to dinosaurs)
- Full synthetic oil
- Mixtures of petroleum and synthetic
Dino 2 Stroke Engine Oil Characteristics
If you have ever gone to an event with racing 2 stroke engines, no doubt you have experienced the smell of a good petroleum based 2 stroke oil. You'll know it when a someone goes by running a good dino oil as the unique aroma will no doubt make you think, "wow that smells good". You will be able to easily pick out the old 2 stroke enthusiasts standing nearby in the crowd as their nostrils will be flairing in and out rapidly and their ears perked up and pointed forward like an alert german shepard about to get tossed a big juicy steak. This reaction is involuntary if you have lived through the old school 2 stroke racing days, it's just in your blood.
Dino oil is typically less expensive than synthetic but with that said, most companies still offer a high grade dino racing oil as part of their line up. Many swear by the combustion and lubrication characteristics of dino oil and I tend to agree that a good dino oil doesn't "fall short" of synthetics in these areas. Don't think of this in the terms of putting longer lasting synthetic oil in your car engine. In a running 2 stroke engine, there is a constant flow of clean fresh oil coating the parts, longer lasting lubrication properties of the oil is really of no advantage here.
The primary disadvantage of dino oil is that it leaves more deposits behind in your engine. Typically an engine running dino oil will have more gummuy deposits on the power valve, and more burnt carbon in the exhaust port, pipe and on possibly on top of the piston. This is a pretty big deal in modern 2 stroke engines as gummy parts and carbon deposits = less performance and more maintenace, BUT to an old 2 stroke fanatic, having that awesome smell is totally worth it :-)
Full Synthetic 2 Stroke Engine Oil
Synthetic racing oils are designed to give us the best of everything. Great combustion properties, great lubrication properties and little or no gummy stuff left behind. When you disassemble a properly jetted 2 stroke engine that has been running a good synthetic oil and race gas, you will be amazed at how clean the engine is. There will literally be nothing on top of the piston, nothing on the power valve and little carbon in the exhaust. In my years of running dirt bikes, I have tried many different oils but I have always gone back to what works the best for me. Amsoil Dominator Racing Oil
seems to give me the best results in my hillclimbers. Very crisp, very clean and great lubrication.
As far as the mixture of petrolium based and synthectic oils, I think you can pretty much come to your own conclusion on that one. They are designed to give you the advantages of both types. Like I said at the beginning of this article, when it comes to 2 stroke engine oil, everyone has an opinion.
Thank You
Jim Marquardt