2000 Yahama 200hp Vmax 0X66sputters at high RPMbs

"Hey Messageboard,

Very Ple

"Hey Messageboard,

Very Please with my Yahama Vmax after several years. I live in Galveston- yes saltwater here. This is my question:

A few weeks ago, I was running at high RPM's and my engine started to sputter then stopped. Then I took it out the next weekend and everything was ok.

I took the boat out on this Wed. 4/16 and it sputtered at take off, low speed and high speed, then it would stop, then start up rpms again.

I did all the necessary maintence myself, change the water/fuel seperator, fuel filter inside the engine cover on the Yamaha, and changed the spark plugs.

I took it out and it ran very good till I went to 4,200 rpms. I went to the local Yahama shop and the guy said I was on the right track. I might need to change the filter in the direct injection~ which he told me is inside an aluminum housing. 4 hours labor and a $78.00 part. Is this easy to change out?

I spoke to a neighbor and he said he had the same problem and it was a bad oil reserve filter on the bottom of the oil reserve unit.

Any thoughts on which way to go?
Hookem2"

"I have a 2001 OX66 225HP. I

"I have a 2001 OX66 225HP. I don't think the OX66 series is "direct injection" though.

Anyhow, I am 99% sure your problem is your low pressure fuel pumps (if they have never been changed). They are defective from that year and should have been replaced years ago. There are three of them, and they are cheap- about $32 each at Boats.net. Easy to replace too.

You should also clean and service your oxygen sensor."

ox 66
means oxygen sensor efi

ox 66
means oxygen sensor efi motor

run a fuel pressure test asap

Thanks for the information. I

Thanks for the information. I ordered the 3 low pressure fuel pumps and will install. Then take it in to get the o2 sensor checked.

Thanks