Low top speed after carb rebuilt

[Nicolasfar]

just rebuilt my CARB on mercruiser 3.0 L , 1988
before hi was able to reach 35MPH AT 4000Rpm
after the carb rebuilt, i bairly acheive 30 MPH at lower RPM and look like if want to die
i did the mixture on the water as the service n’manual states, any clue on what i did incorrectly,

 

[harringtondav]

Two things come to mind. You may have set the float too low. And you may have switched the primary and secondary jets, if your carb has a secondary circuit.

 

[alldodge]

Need to take it back apart and check your adjustments. Also make sure the kit you used was for your carb

 

[TurtleTamer]

Check that the plunger for the power valve moves freely and that the new power valve's stem didn't get bent by your screwdriver when installing.

 

[Scott Danforth]

even before your carb rebuild you had a low top end

go back to the carb

after that, check your compression

your motor should be turning 4600 RPM

 

[Nicolasfar]

I read that those engine compression should be around 150 psi, My compression is 125 to 135 across the 4 cyl , could that explain the low rpm i am able to reach ? i will recheck the float ajustement and other on the carb anyhow
thank you

 

[achris]

Compression readings can vary with the gauge you use. My book says 140psi. At 125-135 I'd say they are fine.

Chris.......