Yami 200hp, 225hp, 250hp, 300hp - same engine w/diff programming and decals?

[Scott]

While reviewing the specs on the Yami 225 HPDI, I noticed that the only published differences (on Yamaha's web site spec page) are:

the compression ratio...

6.2:1 = 200jp, 225hp and 300hp
6.0:1 = 250hp

and the gear ratio...

16:28 = 225hp, 250hp, and 300hp
16:29 = 200hp

Ironically the 225 and the 300 are rated exactly the same?!?!?!

All the other specs apear the same from the displacement of 204.0 ci to the weight of 539 lb

Are these the same motor just "programmed" differently?

http://www.yamaha-motor.com/ou....aspx

[PBCMS]

good question

[rwtzx]

They listed the very early 200's as 225 hp. Who knows the real story, as there are a lot of them floating around. I am thinking it's maybe the porting and ECM that is different.

[Blazenzeek]

Call Nathan at Hydro-Tec. He can tell you for sure.

As I understand it, there are differenes in intake, exhaust, head porting, and cooling. Block is the same.