I was just given a Blue-Jet made by Eska (not a “Jet” drive).  It says 5.1 cubic inches on the front label.  I’ve found that Blue Jets were an Eska brand from 1961-1963.  The Old Outboard Book says there were 3 and 5 HP versions.  I haven’t found a model number (it’s kind of beat up).  Is the 5.1 cu in a 3 or a 5 HP?  Where is the model number?  I’ve learned that both were one cylinder air-cooled Tecumseh powerheads on Clinton lowers.

Thx,

Dave