Twin Yamaha 250 ox66 motors burn differently

[AQUADJ]

I have twin 1998 250hp ox66 fuel injected motors with approximately 750 hrs. One motor had a new power head installed at approximately 600 hrs. The original motor burns about 10% more fuel and oil than the motor with the new power head. Is this normal?

 

[Suncoug]

Re: Twin Yamaha 250 ox66 motors burn differently

Assuming the old motor is in good shape, I would check the O2 sensor.