Mercruiser low RPMs in Forward gear

Pestanaj

Recruit
Joined
Jul 3, 2009
Messages
3
1994 5.7 Mercruiser with an Alpha. In neutral and in reverse, RPMs will max at 4400, while in forward gear it only goes to 2000 RPMs. Out of the water it will go up to 4400 RPMs in all three (neutral, reverse and forward).
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,365
Re: Mercruiser low RPMs in Forward gear

4000 rpm on land is very good,trouble is you wiped out the impeller in the lower unit doing it .Land rpm means squat.Was it serviced with a full tune-up?
prop in good condition?,any bottom growth?
 

Pestanaj

Recruit
Joined
Jul 3, 2009
Messages
3
Re: Mercruiser low RPMs in Forward gear

It has not have had a tune up. The distributor cap had condensation I whipped it dried, no misfire. Prop is in good/great condition and not spun. No bottom growth. Its just weird why in the water it gives me full RPMs in neutral and reverse. In forward at full power its just gives me 2000 RPMs max and will not pass 10 MPH.
 

Pestanaj

Recruit
Joined
Jul 3, 2009
Messages
3
Re: Mercruiser low RPMs in Forward gear

4000 rpm on land is very good,trouble is you wiped out the impeller in the lower unit doing it .Land rpm means squat.Was it serviced with a full tune-up?
prop in good condition?,any bottom growth?

It has not have had a tune up. The distributor cap had condensation I whipped it dried, no misfire. Prop is in good/great condition and not spun. No bottom growth. Its just weird why in the water it gives me full RPMs in neutral and reverse. In forward at full power its just gives me 2000 RPMs max and will not pass 10 MPH. Could it be that I may have move the linkage cable as I used some tie-straps to hold some wires onto the cable?
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,365
Re: Mercruiser low RPMs in Forward gear

With the engine off, push it on full fwd ,full throttle and check to see if the linkage is opening the carb all the way.
 
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