The Seahorse is an outboard boat motor manufactured since 1958 by Johnson Motors. The 35-horsepower (HP) models are printed with the Seahorse logo on the outer cowling for quick identification, but since the printing may have faded or the cowling replaced over the years, another way to identify the motor is by looking at the model number on the engine block.
Clean the side of the outboard cowling (the heavy plastic cover over the motor) to locate the label "Sea 35 Horse" on each side, which denotes both the motor type and the horsepower. If the cowling is missing or been replaced, continue to the next step.
Clean the back of the engine block to locate the model number information printed on a metal plate attached to the engine.
Read the model number to identify the type. For example, the first three characters of model number J35ELUTa refers to a Johnson-built motor ("J") with a 35-horsepower rating.