Gotta be pretty ancient. In the US, there was never a 35 hp model from the late 80's to current production. I assume what you have is a single-carburetor, 2-cylinder, water-cooled motor. Odds are there is a shift rod coupler that can be disconnected to drop the lower unit. If so, disconnecting that coupler will allow you to determine whether the shift rod (upper) is stuck, or if the cam rod (lower) is stuck.
Beware that no parts are available. Unless you can cross reference the water pump or impeller, once that needs repair (about 3 years from new), the motor is done.
