We just purchased a new Tohatsu 6 hp 4 stoke for #387. It was a long shaft model. We paid about $1400 in FLA. I guess Tohatsu is the #1 selling outboard in the world which surprised me. Yes they do make small block mercs as well. We just ran it more or less non stop for 4 days and it worked great. No cavitation even with a 20 degree list during motor sailing. Depending on tide pushed us along at 6 knt at just over half throttle. I too would also recommend a long shaft. I was going to buy a Yammy 6hp but I felt it was too big for the well esp with that fancy gear shifter on the throttle. Was also alot more money.
Guy told me that a charging upgrade would run about 200 bucks since they have to put on a new fly wheel.
The thing that I really like about this outboard is the weight which comes in around 50 lbs. Makes the dreaded engine in and out much less of a chore for old backs like mine. I don't like the engine cover which is a pain to get on and off. Also wished it had a proper dip stick instead of the modified plastic cap/dipstick which I fine hard to read. I guess as the oil gets dirty this will improve!
I bought this motor with many doubts but it turns out to be a great power plant for an Ariel. I guess the Mercs and Nissans would be similar.
I would recommend it to new engine buyers and I'm sure if you shop around you could get a beter price than we did at 1730 on a Sat evening in small town FLA!
Andrew