Brushless motors?

Many applications in our hobby and they have a loyal following.  

Saker, a Chinese company uses them in a lot of their products, they show up in my hand-held chainsaws.  Recently I have had two fail and I think it's the motors that are at fault.  I'm just not sure if I'm testing them properly.  There is no communtator so I'm not sure if I should read resistance or not across the terminals?  I'm reading zero. I do know if I apply battery voltage (in this case 21 volts) across the terminals nothing happens.  

Bugs me because it makes a mess out of my workbench.




New motors are available on-line for less than $10 while the saws run between $30 and $50.  



https://www.bing.com/videos/search?q=brushless%20motor%20animation&view=detail&mid=3FCF447AB1510BB841723FCF447AB1510BB84172&ajaxhist=0