These are from the US distributors as they were provided. I'm sorry my "format" didn't hold up to the transfer. I don't know if Yamaha stopped making engines under 15 HP
SMALL OUTBOARD ENGINE SPECS to 15HP
BRAND MODEL WEIGHT HP/RPM CU INCHES
Evinrude E3RD4 41 3.5@5000 87
E6RG4 55 6.0 123
E6RGL 57 6.0 123
E10RG4 81.5 9.9 209
E10RGL4 103.6 9.9 209
E10TPL4 103.6 9.9 209
NOTES
All outboards are generally rated at 5000 RPM give or take 500.
The difference in weight of same HP engines is probably due to length.
The number 4 indicates 4 stroke engines.
Some manufactures, like Honda, didn't sub list engines with same HP but slight variations in weight.
Large jump in weight is moving from one cylinder to two-cylinder engine.
Honda BF2.3 30 2.3 3.5
BF5 60 5.0 7.8
BF8 107 8.0 13.5
BF9.9 92-107 9.9 13.5
BF15 105-115 9.9 21.4
Mercury 5 Sail Power 59 5.0 7.5
5 Propane 59 5.0 7.5
6 57 6.0 7.5
8 84 8.0 12.8
9.9 84 9.9 12.8
15 EFI 99 15.0 20.3
Suzuki DF6A 55 6.0 8.9
9.9BF 98 9.9 20.0
9.9BT EFI 120 9.9 2.0
Tomatsu MFS2.5 41 2.5 5.2
MFS3.5 41 3.5 5.2
MFS4 57 4.0 7.5
MFS5LPG 60 5.0 7.5
MFS5 55 5.0 7.5
MFS6 55 6.0 7.5
MFS8 82 8.0 12.8
MFS9.9 95 9.9 20.3
MFS15 95 15.0 20.3
Torqueedo 3.0R ? 3000W/6 HP
3.0T ? 3000W/6 HP
6.0R ? 6000W/9.9 HP
6.0T ? 6000W/9.9 HP
Yamaha F15 111-132 15.0 22.1
Interesting. Difference in weight can also be function of Electric start or not. You can also tell from the chart if you can raise the HP on the motor by noting the same displacement for multiple HP motors. On the four strokes it is normally just change the carb which is what I did on my Suzuki 9.9 to change it to 15. It made no difference when it was on the sailboat with the flat pitch prop, displacement hull speed and all, but when I put it on the planing skiff with an appropriate pitch prop to stay in the RPM range, the extra HP was welcome. I actually went down in HP to a 6hp for the sailboat to drop forty-five lbs. of weight on that moment arm mount and the sailboat was much happier.
I wonder if you can change the HP on the EFI models.
Frank, thank you for pointing that out. I noticed that and how the manufacturers played with one set of cubes. I thought that would be helpful for some in choosing an engine that they might want to modify.
There is also the factor that HP is one point but one must consider the boat's hull shape and weight and the correct prop.