http://www.dragonfly75.com/moto/oil.html
NONE OF THESE POSTS ARE MINE ALL TAKEN FROM THE LINK SO IF THE LINK WENT BAD THE INFO IS STILL HERE ON THESE POSTS
All About 2 Stroke Engine Oils
This page has all the best info I could find about engine oils and considerations when choosing the fuel/oil ratio. This is a long read so I want to tell you my conclusions first and then you can read why.
Click here to read about the fuel/oil ratio calculator that resulted from my studies on engine oil. It simplifies this complex subject with its recommended ratios and recommended oils.
OIL TYPES- First we need to change how we talk about types of engine oils. Realize that the descriptive term "synthetic oil" has basically lost its meaning thanks to a court case that allowed oil manufacturers to label highly refined petroleum oil (group 3) as synthetic because it is nearly as good as true synthetics.
There are 5 groups of oils: 1. refined petroleum oil, 2. moderately refined petroleum oil, 3. highly refined petroleum oil, 4. PAO synthetic oil, 5. ester synthetic oil.
So an oil that is labeled as "semi-synthetic" can be highly refined petroleum oil or a mix of synthetic oil and petroleum oil. So it's now a very non-specific term. I prefer to understand the qualities of each type of oil and then read the oil specifications to know exactly what is in it. On this page you can see what is in each oil. Oils not listed here are ones that don't publish the oil specifications or are ones not very popular or not very good.
OIL TYPE RECOMMENDATIONS- I recommend a group 3 oil or a mix of petroleum oil (group 1/2) with true synthetic oil for air cooled engines with iron sleeved cylinders because they need higher amounts of oil for best ring protection and power. For high RPM racing engines I recommend any oil with high amounts of castor oil such as Maxima Castor 927 although it requires more frequent engine disassembly and cleaning of the ring grooves. For water cooled engines with power valves I recommend group 4 or 5 oils for the lack of residues they leave on the valves.
OIL RATING RECOMMENDATIONS- I've always known that a fouled plug is one with too much combustion residue accumulated on it to the point that it won't consistently spark. And I knew that if the fuel/air ratio was too rich that a fouled plug was eventually the result. But I didn't know, before extensively studying the topic of motorcycle engine oils, that engine oil can contribute to that problem if it doesn't match the engine. For high heat engines using NGK # 9 or 10 spark plugs I recommend an oil with a TC/FB/FC rating. For lower heat #6 to 8 plug engines I'd recommend an ashless oil or one with an FD rating.
Street vs Race Engines
A race engine revs to higher RPM and usually just uses the upper RPM within the pipes powerband whereas a street or enduro bike uses a wide range of RPM. So if the engine oil in a street bike is at the right ratio for its top RPM but has a low viscosity index (below 120) then there will be too much oil at lower RPM and it will produce spooge. So for bikes that use a wide range of RPM I recommend synthetic or semi-synthetic oils that have a viscosity index higher than 120.
The Ash Additive
Oils are either "low ash" or "no ash". The word ash is referring to the remaining residue from an oil additive that is one or more minerals (Calcium or Magnesium Phenate) that serve as dry lubricants (for the rings/cylinder and power valves) that can leave an ashey residue when the engine temperature is not high enough to burn it off. So oils are rated as either "ashless" or are rated "low ash" which is either having less than .18% ash (FD rated), or as having less than .25% ash (TC/FB/FC rated). Most oils are TC/FB/FC rated which are made for "high heat" engines. What constitutes "high heat"? Air cooled engines, or high RPM engines (over 10K), or most small engines fit that category. But there is no definitive guideline other than looking at their spark plugs heat range which needs to match the engine heat to have their center electrode get hot enough to burn off combustion residue but not so hot as to cause pre-ignition. So for # 9 or 10 NGK spark plugs I would make sure the oil is a low ash oil for the extra protection it gives during high heat engine temperatures. This information is good to know for reducing engine wear and for reducing occurences of plug fouling. So if you want to foul plugs less often or make your rings last longer then I suggest you make sure you are using an oil that is correctly rated for your engine.
Fuel/Oil Ratio
Some oil manufacturers have known all along how to choose a ratio depending on oil characteristics and type engine use. But they have never shared that with us, probably to be free of liability. So I have come up with a system using the oil viscosities, max RPM, and type of engine cooling to be able to know a baseline amount of oil to use. But ony about half the available oils have their data revealed on the manufacturers websites. I do not recommend anyone buying oils without data because really you don't know what you're buying. They can call it 100% synthetic when in reality it is 30% synthetic (for example the Goldfire Pro oil claims to be a synthetic blend but it only has group 1 + 2 oils). There are no "oil cops" to punish them when they scam with lies. Additives do make a difference but not by a huge amount. All I go by is the oils data, not by any hype the manufacturers try to pour into my brain. I am no longer under their thumb of propaganda and if you read this long report you will be free also and can make smart choices for which oil and ratio you use. If the label says use from 20:1 to 50:1 you will no longer think What-The-*f-word? If they list the data on their site (or if you can get it by emailing them) then you can use my Oil Ratio Calculator to know a moderate amount of oil to use.
