Soling Outboard Mount + Suggestions
I have a 1974 Soling with an outboard mount on the side, which is easily removable. When I bought the boat, it had an old Evinrude two stroke, which weighed in at 35 lbs. I am now looking at new engines, and I think what it comes down to is either a Tohatsu 3.5hp or a Mercury 3.5. It's important to go with the long shaft editions, which are a tiny bit pricier but not much and will save you a lot of hassle. I would DEFINITELY not put a mount on the transom, I have seen photos online of how this looks on a Soling and I certainly wouldn't recommend it, for aesthetic reasons as well as functionality.
The Tohatsu is 45 lbs for the 3.5hp Longshaft, which is not bad and is manageable. When you are ready to sail, you just remove the engine and hang it underneath the deck, beneath the tiller (in front of the rear bulkhead). It's not as perfect as a Saildrive, but that's the price you pay for having such a beautiful boat with clean lines.
The Tohatsu is less expensive at around $950... I remember the Mercury with Longshaft being well over a grand.
I just went out and took a couple photos of my setup for you to get a general idea of what I'm talking about. I tried to attach them but since this is my first post in this forum they are preventing me from attaching images. I can email them to you if you like, or after one more post I will be allowed to add attachments. I also tried to post links to the engines but alas, the forum will not let me do this either as this is my first post here!
I myself am looking for a new engine, and I will be going with one of the above engines... have yet to make my decision.
Good luck and congratulations on the Soling purchase, it is one of the best daysailers around, and when she sits at the dock she looks like a mini America's Cupper... a look that certainly changes with the addition of a transom mount, haha!