Just spent another hour trying to fix this

Its definitely not the connection from relay to starter, its a new (2nd hand) starter, and the connections now very clean and secure.
When the starter turns, which i cant get it to do now, the starter is fine, not slow, or struggling, and i was able to keep cranking it for a while, before it started to slow. So i stopped and stuck battery on the optimate again.
Checked the earths on the bike. It is solid like 0.1 ohm from earthed bits of the bike to the negative terminal on battery.
What i could really use, is for someone with a ohmmeter to go and check what reading they get through the starter motor terminal bolt on the front, to earth on the bike. Mine is readin 0.1/0.2 ohms, which is practically a short circuit, but maybe thats the way these motors work.
The starter clutch cog turns, so thats not stopping the starter turning. Im really hoping its the starter solenoid is dodgy.
Answers on a postcard plz
