New never fueled or run OS 91 FX that was mounted in my RC91 but I never completed the setup. There's a few light marks around the mounting holes. The muffler is all new except the rear cap. The original cap got scratched so this is one that saw just a few runs and is scratch-free.

The engine had a dust cap on the carb while residing in my RC91. Everything operates smooth and the engine has excellent compression.