porsche

1980's Kawasaki ZX10 Starter Motor?

How much rotational force should it exert?
Directly connected to a fully charged battery I can hold the spline with my fingers and stop it turning. Alone it runs at a decent RPM but its got no guts.
I bought a replacement on Ebay and that


Jim has nailed it. Your battery is just about dead (but not flat)
As batteries get older and degrade, an internal resistance builds up which causes the output voltage to drop when current is drawn from the battery.
When the battery is sitting

Outboard starter motor in slow motion

a starter motor engaging at 1/10th speed on an Evinrude / Johnson V4 boat engine You can see the inertial engagement design where the motor starts ...

AMAR Tractor 240-DI

, Horizontal, DI, Water Cooled, Diesel Engine Gears : 6 Forward & 1 Reverse with High / Low Selection Lever Power Take Off : 6 Spline, 540 RPM ...