Don't know about fuel injection, but there are definitely 4 stroke blowers. Personally I prefer 4 stroke for small engines. 2-stroke exhaust gives me headaches.
Small four stroke engines never really got developed, mostly because devices that need tiny engines rarely care about fuel efficiency, and usually care far more about engine weight and cost.
https://www.amazon.com/Makita-BHX2500CA-4-Stroke-Engine-Blow...