While the navy was testing the first two prototypes, they suggested that the third be fitted with the 700 kW (940 hp) Nakajima Sakae 12 engine instead.
Ketika angkatan laut sedang menguji dua prototipe pertama, mereka menyarankan agar prototipe ketiga dipasangi mesin Nakajima Sakae 12 berkekuatan 700 kW (940 hp).