Outdoor Power Equipment and Small Engines - Electric Mower Switch

I have a Black& Decker MM525 electric mower. The plastic handle that switches the machine on an off via P button switch was not working properly so I opened the assembley and discovered that the plastic pin around which the handle rotates was broken. I replaced it with a screw and closed the assembley. The handle worked fine.

However when I started the mower the P button switch (part# 681064-01) started heating up and gave out smoke.
I again opened the assembley and noticed that one terminal of the switch with a black wire had melted.
I am wondering what has caused the switch to heat up. I have ordered a replacement but do not want the new switch to burn out too. I am not an electrician and will greatly appreciate any suggestion/advice from members.


thanks

In electrical system heat is generated when current encounters resistance. This would lead me to believe that either the contacts within the switch were dirty and there was only a small surface touching, generating heat, or that after the motor was started the contacts were separated enough to draw an arc. This may have to do with the pivot point replacement. Make sure that the handle fully depresses the switch.