200 hpdi

[whanlon]

looking for some advice. My motor drops about 1000 rpm when I accel. and surges back and forth.
It runs great with new plugs, but only for about 30 min. It doesn't display any error codes when I hook it up to a computer. Does anybody have any idea what it could be

[Hamfisted]

How's the Racor fuel filter? How 'bout the filter under the hood? Sounds like a fuel restriction problem of some type though. You have the Yamaha Diagnostic System software? What's the O2 sensor readout look like? What kind of oil are you using? Sometimes Yamalube fouls the O2 sensor. Is the oil pump arm adjusted correctly (closed to the stop at idle....) ?


Mike....... Miami, FL