The engine was impossible to tune, and would spit fuel from the carb. Aparrently, most of these Ultimates had the same or similar problems, as Hobby Services now simply replaces them no-questions-asked, and the engine is "Temporarily Unavailable" on Tower's website. Whatever, I got a bigger, brand-new motor for less than I would have paid for it otherwise, and went out and bought a Saito .82 to replace the Ultimate. Wheeee....!