I just purchased a Hobie 21 SC (sail #316) from an owner who never had need of a motor because of his large family of enthusiastic paddlers. Plus, he was very knowledgeable sailor.
He spent over six hours showing me how to rig the boat in his driveway, and how to set it up for safe trailering. Incredibly generous with his time!
By contrast, I only have one crew member, my mentally ill son, who lives with me six months of the year in AZ, and while he can help with raising and lowering the mast, sailing with Richard will be like single-handing the boat.
Accordingly, I decided that a motor is an imperative, and contacted the original dealer in Iowa, who offered to order me the proper mount for $460. He said the bracket that attaches to the stern crossbar is a permanent fixture, and that the extension is removable.
He also said this set-up is designed to carry a maximum of just 30 lbs, and handle 200 foot-lbs of torque. He has been in the Hobie business for 34 years, so I took a chance on him and expect to see the mount before New Years Day.
Does this sound like the right piece of gear... a copy of the original equipment offered for the SC? Thirty pounds means only 2 or 2-1/2 HP, with a 15" short shaft, no reverse drive, and no alternator.
However, I thought the SC options included running lights, which would require a battery and alternator, hence a bigger motor, at least 4 HP, and a stronger mount to support 60 lbs.
Not to mention the potential need for a longer shaft to keep the prop in the water, which is also only offered with the bigger motors, 3-1/2 HP and up, which weigh 45 lbs or more.
Anyway, I have made a deposit on a 4 HP Yamaha, with a long shaft, reverse, and no alternator option, that only weighs 50 lbs. It is the lightest motor in this category.
Some real-world feedback would be welcome.