It really depends on the model and when they were made. Jonies for the last 25 years or so have been 50-1 engines. A Mac might need something more like 30-1 or richer depending on how old it is, or it might be a 40 or 50-1 machine.
FWIW- I have saws dating from the early 60's up. I tend to run about 40-1 in all of them with no problems. But you want good 2 cycle oil, not outboard oil and certainly not motor oil! The biggest reason the old engines used 16-1 or 20-1 was because the lubes were so poor back in the day. With a good 2 cycle oil, assuming the saw isn't worn out or has been abused, I think something in the 35 or 40-1 range will work for most saws. There will be exceptions that simply require a richer mix due to specific wear, design or conditions. IF the saw will run good at 50-1 then that's what I'd go with. Too much mix oil is almost as bad as not enough.
This post was edited by Bret4207 at 04:11:57 09/25/12.
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