Yamaha makes a good product.
The HPDI is High Pressure Direct Injection.
Supposed to be better on fuel.
Do a compression test and check any service records?
They're also more expensive to fix should anything go wrong?
Maint. on any motor is important, these motors it's critical.
Proper oil, proper additives(ring free) and frequent filter changes.
Use Yamaha parts/filters.
