Decalin Additive Rotax 582

According to this, a Sunoco near you sells E0 unleaded 91: 

https://www.pure-gas.org/index.jsp?stateprov=CO

In my opinion, any Rotax engine consuming 100LL would benefit from the use of Decalin.

It depends on your configuration.  

Decalin converts the lead to lead phosphate, which goes out in the exhaust in a sort of (carcinogenic) powder.  Without it, lead oxide accumulates in the oil, on valves, etc.  However, I know a CFI (and Rotax heavy-rated mechanic) who claimed that the powdery lead phosphate started to cake on the flex hoses in his particular exhaust system, which made them stiff and untimately caused them to fail. So he has resigned himself to using 100LL without Decalin, and just changing the oil a lot more often.

I doubt that the Declin will be of benefit to a two stroke. There are no hot poppett valves nor oil circulatory system to contaminate. I know racing two stroke bikes whom used 100LL with no problems. However I do not have any longterm exerience myself others might.

I agree with Glen!
A two stroke does not have any Oil to contaminate, it is constantly being replaced.
There are no Valves.
What exits the cylinder goes out the exhaust along with the Oil Spray.
100LL in a Two Stroke should Not be any problem.

And as Tyler posted,  UL91 E-0 is available at the Sunoco right in town.
It is probably labeled as "Boat/Marine Fuel" on the pump.