Drastic? No. 20W50 is what I've been running for the entire life of two of my motors. I'm pretty sure it's what's recommended.

I wouldn't talk to regular 'car guys' about rotaries. They come up with some wack ****.


I would start looking at the ignition system. When was the last time you changed plugs + wires? Test it for spark.

 

Plugs have less than 4k, so do the wires.

tl;dr Blown rotor. Sufficient power loss, horrible acceleration. FC Grounded.

 

Have you pulled out one of your trailing (top) plugs, pulled out your EGI fuse + cranked it over? If you hear three even whooshes, then it's not blown. Then you can try a compression test w a piston engine tester.