750sx slow start charged battery 3 starters

[26slate]

Got this pos 750sx with spark plugs out motor spins free by hand took pump off to eliminate pump being locked up .. Fully charged battery even jumped it off a Silverado no spark plugs starter spins fast with spark plugs in chugs and feels like battery is dead iv user 3 different started (all used ) thoughts guys ???

 

[Magnum Mike]

check the voltage drop across the battery cables, or try a different set of cables.

 

[26slate]

check the voltage drop across the battery cables, or try a different set of cables.

Fixed it I made new ground cable had that problem with a 650 once out at the river !!! She's alive !!