Oh boy, two-smoke oil! :lol:
These threads are the secret to eternal life, as they never die. Why? Because there is no one answer. Every engine is different. My hopped up chainsaws will not tolerate a 100:1 oil ratio for long. A stock high-performance saw likely wouldn't either. The lower connecting rod bearing is likely to be toast in no time. However, my (stock) leaf-blower or a hedge-trimmer would likely do just fine on the 100:1. In fact, the actual oil ratio really isn't all that important. I run a high-viscosity racing oil (for the benefit of said hopped-up saws) at 40:1 in ALL of my two cycle and 4-Mix equipment to no ill-effect, even though the OEM recommends a 50:1 mix. Pistons and plugs stay clean, so do the muffler screens.
To go the other way, there is no need to mix up a special batch of 16:1 SAE 30 non-detergent for most vintage equipment you may have either. Barring anything that makes extensive use of plain bearings or known to have rough machined surfaces, modern oil mixed at 32, 40, even 50:1 should do just fine. Again, I personally shy away from 50:1 just because of my tendency to run high-perf or vintage saws but 50:1 is certainly do-able in old iron.
The only real hard and fast rule is to make sure the oil you use is designed for use in air-cooled engines. The operating temperature range of your typical air-cooled OPE engine vs a bike/atv engine, sled, or outboard all vary significantly with specific oils blended to cater to each category's needs.
These threads are the secret to eternal life, as they never die. Why? Because there is no one answer. Every engine is different. My hopped up chainsaws will not tolerate a 100:1 oil ratio for long. A stock high-performance saw likely wouldn't either. The lower connecting rod bearing is likely to be toast in no time. However, my (stock) leaf-blower or a hedge-trimmer would likely do just fine on the 100:1. In fact, the actual oil ratio really isn't all that important. I run a high-viscosity racing oil (for the benefit of said hopped-up saws) at 40:1 in ALL of my two cycle and 4-Mix equipment to no ill-effect, even though the OEM recommends a 50:1 mix. Pistons and plugs stay clean, so do the muffler screens.
To go the other way, there is no need to mix up a special batch of 16:1 SAE 30 non-detergent for most vintage equipment you may have either. Barring anything that makes extensive use of plain bearings or known to have rough machined surfaces, modern oil mixed at 32, 40, even 50:1 should do just fine. Again, I personally shy away from 50:1 just because of my tendency to run high-perf or vintage saws but 50:1 is certainly do-able in old iron.
The only real hard and fast rule is to make sure the oil you use is designed for use in air-cooled engines. The operating temperature range of your typical air-cooled OPE engine vs a bike/atv engine, sled, or outboard all vary significantly with specific oils blended to cater to each category's needs.
