Oil Mix Ratio's Made Easy
I have raced motorcycles for years. Those 2 Stroke engines require pre-mixed oil and fuel, just like some of your common weed wackers, chain saws, or other gas powered tools. There are a number of tools and graduated cylinders or measuring devices you can use to get the right mixture of oil and gas each time. But what do you do if you don’t have one of those around, or you’ve lost it? Here’s an easy explanation of how to calculate the correct oil mix amounts…
First of all, the mix ratio is normally set by the engine manufacturer. Those little weed eaters can have a mix spec showing you a number like 40:1 (forty-to-one ratio). This means that for 40 parts of fuel you need to add one part of oil. So if you wanted to mix up a single gallon of oil/gas to run your tools, who much of each do you use? Just remember the number 128. That’s how many ounces are in a gallon.
Anytime you want to mix up a batch of premixed fuel for yourself, just divide 128 by the ratio number specified by the manufacturer for your tool. For example – if the ratio for your wee-eater is 40:1, then you divide 128 by 40 to get 3.2 – which is the number of ounces of oil you need to add to a single gallon of gasoline to create a 40:1 mix. If you need 25:1 for your chainsaw…. 128/25 = 5.12 ounces.
Now you can also use all those other scientific measuring devices too – like a Ratio Rite and others. But in a pinch with no other means you really need to know how to set up the right mixtures yourself. I’ve even had occasions when out riding dirt bikes where we would stop at a country gas station and want to fill up for the return trip. With no mixing device you are quite possibly screwed. But I could easily calculate that for my 2 gallon tank and an 80:1 mix ratio, I needed 3.2 ounces of oil added (128/80 = 1.6 oz per gallon). Then I just buy one of those 5 Hour Energy drinks and (after drinking it and rinsing the bottle) use that to measure out the correct amount of oil needed. The 5 Hour Energy bottle is 1.9 oz, so it takes roughly two of those filled with oil in a 2 gallon tank on my dirt bike.
Pit Posse PP3240 Ratio Rite Premix Gas Fuel Oil Mixer Mixing 2-Stroke Measuring Cup With Lid
Manufacturer: Pit Posse
Brand: Outlaw Racing Products
Part Number: PP3240
Amazon Price: $9.86