2006 9.9 to 15 hp. MSH Two Stroke Upgrade

Hello all, I found this forum by accident and possibly someone here could solve my mystery. I have a 2006 9.9 hp. two stroke outboard that I bought new for my son's inflatable. We now want to get a larger inflatable and wish to pump up the hp. a bit. I was told that the carb and exhaust tube are the difference between the 9.9 and the 15 hp. I have looked a the parts breakdown of these two models and the carb. part # are the same and there is no listing of the exhaust tube. I did find the reed valves have a different part#. Can someone provide the answer to what the difference is and the part numbers if any ?

Thank you
drew

Nice Website!!

[boats.net]

I don't make horse power conversion, maybe someone here else has tried and give you an answer.

The 9.9 and the 15 hp. yamaha two strokes in 2006 have very subtle differences to increase the hp. between the two models. If I had a good parts breakdown of the two models I could determine the difference and see if it is worth the cash. So far I think the reed valves have a different part number but I have been told there is possibly exhaust changes.

Thanks