Not to hijack this thread but I have a question about the mix ratio. For years, I have been running our saws at a 50:1 ratio and never had any major problems. I am thinking about starting to use a 40:1 ratio. First thing, the oil I buy comes in 5.2 ounce bottles which is for 2 gallons of gas at 50:1. I have never seen bottles made for a different ratio. According to a calculator I found online, it says I would need 6.4 ounces for 40:1. When using 5.2 ounce bottles, how do you get exactly 6.4 ounces? Do you use a measuring cup, do you weight it?
Another thing is on my JD CS56, will I notice a difference when going from 50:1 to 40:1? Will the saw have to be retuned? Are there any disadvantages in running 40:1.