I have a string trimmer, Cub Cadet BC509. I have the trimmer for four seasons and an very happy with its performance. I have added line numerous times in the last four years from the spool of line I purchased at the same time as the trimmer. Point being there is nothing new.

The last time I used the trimmer I had to add new line. I pulled about 30' of line from the spool, and wound it per the instructions. I used it the rest of that mowing session. This morning I got out the trimmer and completed about two thirds of the yard and the string broke. I took the spool off, fished the line out, put them in the two slots to hold them until the spool was in position. When I pull the ends to release the line, all of the line on the spool unwound like a spring.

I repeated this several times, and each time the same results, just as I had the spool in place, the line unwound and I had to start over.

Has any one else experienced this, and if so what is the solution?