2000 S22 Running rough at 1400-1500 RPM

[mixpro55]

I just had an oil change new fan belt and a new set of plugs .Denso SK 20r11 and a new fuel filter .The boat has 410 hours and i thought it was about time for the service .It ran great before it was serviced but now its running rough at 1400-1500 and a little slower out of the hole....Anyone have any ideas on this  ?  Thanks Dave 

[Avidx22]

Hi Dave,

Problem may be that they didn't gap the plugs properly. Of course it could be that the fuel pressure regulator is going...as a coincidence.

I'd check the plugs' gap or the fact that you may have a bad plug. It happened to me before.

Garret/AvidX22

[mixpro55]

Thats a good place to start . Its weird because it ran great before we changed the plugs  .Thanks for your ideas  ...Dave

[ktdust]

Clean the mass air flow sensor. It may have gotten dirty from the old serpentine belt.

[mixpro55]

I sure thank you guys for your help ! And if you have any more ideas let me know  .    Dave

[blindside]

Water in the gas probably. There are going to be lots of poor running boats with the ethanol fuel.  Get a good fuel additive like sea foam.