"Jeff, as far as I know, the o
"Jeff, as far as I know, the only 2 strokes built by Tohatsu were the single cylinder 4 and 5 horse motors bearing "product of japan" on the tag.
Ian, yes, the Tohatsu built Mercs are pretty much pure Tohatsu.
There was an early (1999/2000) "R" series of motors that had a couple minor modifications specifically for Merc, but that quickly went away and now they are identical.
Yamaha built two different series of motors for Merc over the years.
There was the Yamaha Mariner line which was pure Yamaha - carbon copies of earlier Yamaha models.
Then there was the regular Merc line (which includes the Merc/Mariners).
Yami either built components or complete outboards to Merc spec and they often contained a mixture or blending of both Yamaha and Merc parts (which in my opinion produced some of the most superior outboards ever to hit the market).
You would often find Mercs to have Yamaha built powerheads and gears with Merc's Thunderbolt 4 ignition, a Merc gearcase and Walbro carbs - super well built, ultra-reliable motors.
The bottom line for me comes to this. If you want a 4 stroke motor, spend the few extra bucks and get a Honda. Their design, engineering and reliability is second to none - although they do have a habit of discontinuing the parts right along with the model when they stop production.
Your second choice in a 4 stroke should be Yamaha. They design from the drafting pad on up - so you don't get a cobbled together model.
I wouldn't touch another 4 stroke on the market today - they are still trying to work out all the bugs and unlike a 2 stroke, a 4 stroke needs to be cared for to the letter of the factory maintenance chart or you quickly have a couple hundred pounds of scrap metal on your hands.
If you are looking in the 30-40 horse class of motor, why not consider a 2 stroke direct injected.
Tohatsu has the 40 TLDI and Evinrude produces the 40 ETEC - both superior choices to any 4 stroke currently on the market in that horsepower class in every respect - faster, lighter, just as clean/quiet, cost less initially to buy and cost way way less in maintenace..."