!997 OX66 250 Stator question

Tatt00z

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Good afternoon friends. I have a quick question I would like to bounce off you all before I spring for the stator.
Everything I have read, and researched points to the stator. My question is I talked to a Yamaha tech, and he had me check a few things before he came to the marina.
Told me to check the fuel pressure from Schrader valve, which on good motor was 37, never moved much even under a load. The suspected motor, which only fires on 3 cylinders on same side, pressure was 47, and the needle was moving frantically between 37 and 50. Under a load didn't really move much. My question is, good a bad stator and a bank that only fires on one side cause the erratic pressure on that motor. The tech told me that the motors didn't work like that, meaning nothing just controls one side of the motor, but everything I read, seems to contradict him. Anyway, thanks for any and all help.
Glen
 

Andrew93

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I would really triple check the fuel system before you replace the stator. There is a filter on the fuel pressure regulator that if clogged or obstructed can cause increased fuel pressures. I know the motor drops cylinders when at idle and warmed up which might make it look like not all cylinders are firing.

The OX66's are usually fuel related issues, even when all else might point towards electrical. Check the whole fuel system including low pressure fuel pumps, VST filter, fuel pressure regulator filter, etc. good luck and keep us updated!
 

Tatt00z

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Thanks medic for the advice. We changed the stator, and the boat ran flawlessly, put the pressure gauge on and it matced the starboard engine at 37psi.
What a relief, found the stator online used, but guaranteed for 250.00 shipped.
Thanks again, now bring on the fishes.
 

seasick

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Tatt00z said:
Thanks medic for the advice. We changed the stator, and the boat ran flawlessly, put the pressure gauge on and it matced the starboard engine at 37psi.
What a relief, found the stator online used, but guaranteed for 250.00 shipped.
Thanks again, now bring on the fishes.
I don't understand how a bad stator can affect fuel rail pressure. Perhaps someone can educate me.