Mercruiser 5.0 sputtering

[dhkissel]

My 2000 Mercruiser 5.0 has been sputtering off and on. Had the plugs replaced, fuel pump new, oil pressure sensor replaced, had the fuel pickup tube checked. Over 3000 RPM the engine starts sputtering. If I slow it down to below 3000, it runs better. My next thought is the carbuerator. I did notice that the flapper stay wide open even when idling. Any thoughts or help where to look? I'm pretty new to boating and engines.

 

[dubs283]

Re: Mercruiser 5.0 sputtering

the "flapper" you refer to is probably the choke plate - its supposed to stay open at all rpm's on a warm engine

sounds like your parts replacement is all over the board - plugs should be replaced as part of a tune-up which includes many other components of the ignition system

the water separator is a good location for a quick inspection of fuel quality

if you post a serial number for your engine it makes it easier for folks to narrow down the possible problems/places to look for trouble

 

[dhkissel]

Re: Mercruiser 5.0 sputtering

The serial # is 206538

I'll take a look at the water separator, but if it was a fuel issue, would I see the problem at all speeds? I currently just see the issue at increased RPMs.

Thx