OK, I toke the lawn mower apart.
Battery: two in series, 12V 17.2AH sealed lead acid battery.
Yuasa-Exide, Reading, PA. 19612, Part Number YLM18-12.
The motor top has two copper type of brushings. The brushing holder is
spring loaded, and screw mounted.
It seems the brushing can be replaced. The width of the brushing is half
Any where I can get replacement brushings?
Finally able to unscrew the blade (18 inches long), counter-wise to unscrew.
Cut my knuckle.
Will get a replacement blade at Amazon.com.
Still do not know best to test if the motor or battery has problem?
Thank you all for your advise.