4.3 down on power

[Stingray1961]

This year took the boat out 1993 stingray 4.3 mercruiser boat struggled to plain rpm won't come up. Rebuilt carb fuel filter changed new plugs cap rotor timing checked . Good compression any suggestions

 

[alldodge]

Need more info, what was it done during winterization and what was done to get it ready for this season?

Good compression, what were the numbers and when did you take them?

 

[Stingray1961]

150 this spring boat hasn't had the power it used to but this year it got worse. I winterize like I do every year fog it down do
Lower unit

 

[alldodge]

Still know very little about the motor so lets start with fuel pressure, it should be between 4-7 psi from idle to WOT

 

[Stingray1961]

Fuel pressure is fine timing fine plugs fine already checked all that