On Sat, 14 Nov 2020 19:44:03 -0800 (PST), True North
wrote:

On Saturday, 14 November 2020 at 23:10:58 UTC-4, Keyser Söze wrote:
On 11/14/20 9:53 PM, gary hess wrote:
can anyone tell me the difference?

The "high thrust" motors typically have larger lower units, higher gear
ratios, and different props than "standard" outboards , but I believe
the powerheads are the same in both types.

--
*Lock Trump Up!*


Yes, that was the case with the Mercury 60 Big Foot that came with the 16 and a half foot Legend bow rider I owned a few years ago. They claimed it had the same lower end as the 90 and had a special larger high thrust propeller. I believe it was originally popular for pontoon boats.

The big foot(Merc) high thrust (Yamaha) allows a larger diameter prop.
The bigger L/U on a light mono hull is probably not a good idea. The
standard model will get you a little more speed because of less drag.
If you look at the L/U on racing hulls the first thing you see is a
very thin gear case. The advantage of a big foot on a work boat might
be useful but not a speed boat.
If you have a pontoon or other displacement hull, swinging that bigger
wheel will give you much better low speed performance, like docking in
the wind and have minimal WOT impact since you are basically pushing a
brick through the water anyway. If you have a ski boat, that extra
thrust will help you yank skiers out of the water faster but people
don't typically have the 40-70 HP motors on ski boats.