2005 yamaha 9.9t to 15hp modification

[Cocoa Beach Terry]

I am considering a 2005 extra long shft motor for my 30 foot sailboat. It will need 15 horsepower to do the job. I just got off the phone with Yamaha Tech and 2005 and 2006 seem to share displacement (19.7ci)and we even looked up camshaft part numbers, which are identical for those two years. Has anyone had experience putting a 15 horsepower carb onto the 2005 or 2006 9.9?

 

[ondarvr]

You need to look at the parts diagram for each and compare the numbers, frequently people will say it's just a carb swap, then after the fact find out there are many more parts that are different.

​A 9.9 high thrust model would probably be better.

 

[Sea Rider]

If both mentioned models have same CC, check if 9.9 OB shares same carb as the 15 HP model, is so, there should be some other form of restriction as carb/timing advance, prop ? check both model parts for similarities.

Happy Boating

 

[boobie]

Couldn't Yamaha Tech give you the exact answer ??

 

[jimmbo]

The pistons, heads, intake manifold, and valves could be different