If your Y-Axis chart titles are truncated in Excel, there are a few things you can do to fix the problem:

1. First, try increasing the width of the column that contains the chart title. To do this, click on the column header and drag it to the right.
2. If that doesn't work, try wrapping the text in the chart title. To do this, double-click on the chart title and go to the "Format" tab. Then, click on "Text Wrapping" and choose "Wrap Text."
3. If neither of those options work, you can try adding a line break in the chart title. To do this, double-click on the chart title and press "Alt+Enter" on your keyboard.