I believe the Novarossi & Axe Rossi use the same turbo plug taper between those two brands. The OS plugs I believe may only work on the Picco engine. I would take the head button off and check it to make sure though, but for sure, the Novarossi it will not work. The OS taper is too large and will push the novarossi button chamber in.
Kyosho, Mugen Seiki, Maxy's Fuel, KO Propo
O.S., Ninja JX, Novarossi, RMV