Replaced starter relay & it still doesn't start so my husband tried to pull start a couple of times. After that tried the electric start again & it tried to start but went back to making a screeching noise but still tried to start.

 

Make sure the battery is ok as even a new battery can drop under a load. You can load test one with a meter as this site shows.https://www.batterystuff.com/blog/ho...ry-is-bad.html If the battery checks out ok,the screeching could be from a worn one way starter clutch depending on which model you have.