Any experts on Yamaha 9.9 High Thrust outboards out there?

[fredrussell]

My Super Seal 26 has a 2006 Yamaha 4-stroke 8hp outboard. I would like a little more oomph so I'm considering replacing it with the 9.9hp high thrust version, which, as I understand it, would be more suited to my needs.

Does anyone know when Yamaha switched the 9.9 high thrust from being based on the 8hp power head to being based on the 15hp power head? The reason I ask is that the larger (in physical size) outboard will not fit in my outboard well. As it is, the well has been adapted slightly to take its current Yamaha 8hp motor (boat originally had a more compact 2 stroke engine), and the high thrust outboard based on the 15hp simply will not fit.

I hope that makes sense - I'm trying to find out which years the Yamaha 9.9 high thrust engine was based on the 8hp power head. I will be buying second hand so need to know the years to aim for.

 

[rodpage]

Up to about 2001 in Europe (although in small numbers after 1998). The FT9.9A models share a block with the 8hp and the subsequent FT9.9C share a block with the 15hp. FT9.9A variants were available up to about 2006 in the USA/Canada. The FT9.9A (or F9.9A some years) started production in 1985 with some improvements over the years.

Some serial number lists can be found at http://www.claus-schalhorn.de/ybaujahr.htm

The shop manual for the late model FT9.9A can be found at http://www.inadee.co.uk/documents/F9.9MLHD.pdf

 

[fredrussell]

That's fantastic, many thanks.

 

[QBhoy]

Have you thought about going to a late model 2 stroke ? That will sure give you more ooomph. They aren't cheap though ! Very sought after.
The 8hp yamaha 2 stroke is widely considered one of the best engines ever made. Suppose that why they command a premium price. I have two....no need at all, other than I'm a total boat geek and can't pass up on any sort of opportunity ! Haha.

 

[QBhoy]

Another engine that may meet your needs and more is the excellent Late model mariner or Mercury 10hp 2 stroke. Bags of power and nowhere near the size and weight of the 9.9 4 stroke yam.
To put it in perspective about the 2 strokes...the 8hp yamaha 2 stroke weighs about the same as the 4hp 4 stroke yamaha. For hat size of engine, the fuel consumption difference is almost negligible

 

[fredrussell]

Cheers for info on 2 stroke options guys, but I'm a 4-stroke fan really. As outboard is in cockpit well it needs to be quiet as possible. The yamaha 4 strokes are very good in that respect.

 

[alahol2]

The 9.9 high thrust Yam is a stupendous engine. We used it on a 32ft catamaran, it would push it along at 6 knots all day long. I don't think there is a 2-stroke on the market that could come anywhere near it, they are just not designed for displacement boats.

 

[QBhoy]

At the risk of an argument, I think it's well known that the 2 stroke motor murders any 4 stroke with its torque figures. You e surely seen the videos of the tug of wars between 2 and 4 strokes. All end up with the 4 stroke powered boat being pulled under water.
Anyway, all yamahas are great and I totally understand the quietness and refinement given with the 4 stroke.