Force twin120hp Slow Cranking

[MightyMidget]

I had the motors running after getting the boat, I saw there was no water flow on each so I shut them down. I pulled the lower units and sure enough the water pump impellers were shot, I replaced them and put back together. I also pulled off the thermost housings and found them both to be stuck open. I got new ones and replaced them. Now the motors turn very slow even when I use both NEW batteries. I got 1 new starter to see if that was the problem but everything is still the same. If I pull the plugs it turns over fast, PLEASE HELP.

 

[alldodge]

Welcome

How easy is it to rotate the motor by hand with plugs removed?

 

[racerone]

How did these motors run for you last season ?

 

[MightyMidget]

Welcome

How easy is it to rotate the motor by hand with plugs removed?

I can turn it by hand fairly easy with no plugs in...

 

[MightyMidget]

How did these motors run for you last season ?

I just get the boat and was told they ran fine...owner bought a bigger boat this year

 

[alldodge]

Remove Bat cables at both ends and clean them to shinny metal.

 

[racerone]

Bad water pump impellers , but it ran fine??----Post the actual compression numbers here.----Need to evaluate these engines before spending any beer tokens on them.

 

[jerryjerry05]

Compression test?
It's odd that BOTH motors turn slow.
Test the batteries?
Check the cables for bad spots and loose connections, battery switch could be going bad?