2003 Mercruiser 5.0 305

cliffkat

Recruit
Joined
May 8, 2012
Messages
4
I have a 2003 Chaparral with a 5.0 liter 220 HP, 305 CID Alpha Sterndrive. The motor serial number is OM627259. The boat cranks fine, can run it up to 3300 RPM and cruise around all day at 28-30 MPH with no problems. Whenever I try to accelerate above 3300 RPM, the boat begins to surge. Fresh gas, ethanol treatment and a new fuel filter. The boat still does the same thing. WOT is 4400 to 4800. Could this be the electric fuel pump? If I tested the fuel pressure, can the test be performed with the boat out of the water, not under a load? What should be the test pressure? Lots of questions, thanks in advance for assistance.
 

Bondo

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Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: 2003 Mercruiser 5.0 305

I have a 2003 Chaparral with a 5.0 liter 220 HP, 305 CID Alpha Sterndrive. The motor serial number is OM627259. The boat cranks fine, can run it up to 3300 RPM and cruise around all day at 28-30 MPH with no problems. Whenever I try to accelerate above 3300 RPM, the boat begins to surge. Fresh gas, ethanol treatment and a new fuel filter. The boat still does the same thing. WOT is 4400 to 4800. Could this be the electric fuel pump? If I tested the fuel pressure, can the test be performed with the boat out of the water, not under a load? What should be the test pressure? Lots of questions, thanks in advance for assistance.

Ayuh,.... Welcome Aboard,.... Is this a Carbed motor, or Efi,..??
 
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