Tuning Up A 40hp Yammie

[Steve O]

I've got a 2001-2002 model 40hp 2 stroke yamaha. i've heard that it is possible to "tune up" a 40hp to a 50hp because they've both got the same block (693cc). Would it be possible to tune the motor up by changing the carbs and silencer??

Any input is appreciated.

Cheers,

Steve

[pelican]

Firstly - will your boat take it?

The only way to check if all parts are the same is to look at the official parts diagram and go through every part to see what is differnt.

Extra HP can be as simple as a restrictor plate and carby jets or a throttle all the way to heads , ports , exhaust,piston shape, head gasket, reeds, carby, manifold or airbox.

Except on some very early models it is not ecconomical to do it with new parts and the manufacturers know it.

Do the search on the parts list and see what parts are required and price it up to see if it is worth the hassle.

Pel

PSLook at the torque curves of the different motors as if it achieves the extra hp only at high revs and not more torque unless you need top end speed and a bigger fuel bill on day to day you won't achieve a lot.

Edited October 22, 2008 by pelican