Yamaha Outboards

[sergio]

hey anyone here has a yamaha 9.9hp motor ? apparantley there is a kind of modification which you can do to change the motor into a 15hp . my friend did it to his yamaha and all he had to do was change the plunger of the carburettor . it's supposed to be coming back from the mechanic soon . will give more info soon , right after we try it out

[skip]

Hi Sergio,

My cousin had the same engine and did the same mod. Though I believe it involved more than just the plunger in the carb. More like different jets in the carb etc, mainly carb mods, not sure if it went as far as a different carb but the block is the same as the 15hp.

Skip

[sergio]

hmmmm I thought it was kind of too simple to just change the plunger . I'll tell my friend to talk to the mechanic so we'll see what we can do. thanks for the info though

[CaroMalta]

Any Idea how much this modifivation costs? Cos From where I bought it, they charge 35Lm.... Is it wortit?

[skip]

I would say Lm35 is a bargain considering the power increase you get from a 9,9 as a 15hp. Definately a worthwhile mod as the engine retains the same weight and therefore the boat perfoamance is greatly increased. You can load it down more and get the same results.

For Lm35 it's a no brainer

[Destination Sea]

Hi
I think that adjustment to the cam advance is also required.I am not sure on this engine but others need this without  rejetting than. It all stands to the setup specifications at the factory.

[suffrun]

I also own a 9.9 yamaha outboard and am interested to upgrade it to 15hp. Does anyone know of a good/reliable mechanic?

[LapsiBoy]

Take it to Gasan. I think it's best because they know exactly the thing to do. A friend of mine tried to do it himself (You have to bend somethin) and over did it which lead to the outboard working like a lawn mowwer! hehe

[suffrun]

makes sense lapsiboy, thanks.