The oil that is formulated @50-1 clearly states on the bottle that it works in ALL 2 cycle engines. If your going to use the older type oils, follow the recommended mix from manf.

Virtually all modern equipment companies have their own branded oil and its going to be 50/1. These companies also say their older engines are perfectly safe on 50/1 when using modern 2 stroke oil labeled for 50/1. Modern oil is so much superior to the older oils that the practice of mixing 50/1 is proper.

The only engines where this may not apply would be the very old units, say 30 years or older that were designed and jetted to run on automotive 4 stroke oil. These were designed to be 25/1 or thicker. Because the jetting and clearances were designed for 4 stroke oil, days prior to 2 stroke oil being available, those older 2 strokers may have issues with 50/1. Otehrwise, unless you have one of those very old engines you should be perfectly safe using 50/1 when using 50/1 stroke oil that is specifically designed for outdoor power equipment. This does not mean you can use all purpose 50/1, anything listed as good for water cooled engines such as outboards or liquid cooled motorcycles is not outdoor equipment specific.