Yamaha definitely does not use Tohatsu for their small Enduro's, nor for their export 2-strokes. Those two are fierce competitors in that market. Mercury and Nissan do use Tohatsu, but Nissan is out of the 2-stroke business completely.

Tohatsu currently still makes two ~10hp 2-stroke engines - the 9.8 and the 9.9. The 9.8 is based on a 6hp (as is the 8hp), and is the same as your Nissan 2-stroke. The 9.9 is based on the 15hp. Regardless of badge rating, the 9.9 is a much more powerful engine than the 9.8 (I have used both).

You can see for yourself: http://www.tohatsu.com.au/outboardengines/2stroke

I have already given the difference in weight of our 20hp 4-stroke Suzuki and the 15hp 2-stroke Yamaha Enduro - the difference is 8lbs, but the Suzuki has 5 more HP. The difference with the Tohatsu 18hp 2-stroke is 7lbs.

The Yamaha 2-stroke 20hp weighs 106lbs - 9lbs MORE than our 20hp 4-stroke Suzuki!

Look closely and you will no longer see 20lb differences between available 2-stroke and 4-stroke engines (and I just showed you that the case reverses for many of them).

The Honda 15 and 20HP (same engine) weigh 101lbs - 12lbs more than the Enduro 15 but 5lbs LESS than the Yamaha 20hp 2-stroke.

The Yamaha and Tohatsu 4-stroke 15/20 are beasts at 114lbs - which does get to 20lbs more than the Enduro 15 - but they are also undergoing a redesign right now to compete better with Honda and Suzuki, so that weight will not hold much longer. And they are presently only 7lbs more than the 20hp Yamaha 2-stroke.

The same is true smaller than 15hp. Simply look at the links I provided for Tohatsu and Yamaha. Those are relevant brands because they are by far the most prevalent choices in the Caribbean.

In the US, it is all moot because you cannot buy a 2-stroke. This point is probably the reason why everyone there thinks 2-strokes are much heavier than 4-strokes - nobody there has paid any attention to the current state of comparison.

I know I hadn't until it was time to get a new one. Then I got disabused of my notions.

Mark