Drop down menu spacing

Hi and thanks for your help in advance!

I’m trying to space out my menu items on my site (http://automotivetestequipment.co.uk/)

I have used the css below to space out the menu items:
#nav-second ul.sf-menu>li {
width: 32.5%;
}

it worked and they appear to be equally spaced which is what I was looking for, however I need to fix the problem of the dropdown menu on the “Products” menu item; as you can probably see it is shifted far too much to the left.

the menu navigation I used is the secondary menu, I would appreciate any help at all!

Many thanks