Hydrotech fatshaft for Yamaha 250 HPDI is this a good idea?

[Jefff]

Hello
Looking at purchasing a 250 Yamaha hpdi Andy it has a new hydrotech fatshaft gear case with low water pick ups on it. I know nothing about Yamaha hpdi motors let alone this gear case. Any input on gear case and motor is appreciated, thx in advance.
jeff

[walnutshoe]

The case mods benefit folks that surface the prop. Normal PTP heights you won’t notice much difference to stock case.

[CJ1]

And if you surface it alot depending on boat you may be without a prop and half a shaft with the stock unit. So depending on boat it is a nice lower. As far as the engine if you are good with maintenance and run good premium fuel. You will be fine. If you are not and store the boat or not run it for months at a time with old or poor fuel you will soon have a blown power head. Cj

[GregGuimond]

Good strong motors but proper filter maintenance is a must. IMO running 89 is aok in the HPDI but not 87 which is what Yamaha called out for that motor.

[yam911]

Good strong motors but proper filter maintenance is a must. IMO running 89 is aok in the HPDI but not 87 which is what Yamaha called out for that motor.

Yamaha calls for a minimum of 87 octane. As in more is OK. Less is not.

But as you note, running 89/91/93 is much mo better.