Hi im after the fuel mixture for a 125L husqvarna straight shaft brush cutter.thanks

From you manual:
Two-stroke oil
For great results and performance use HUSQVARNA two--stroke oil, which is specially formulated for our two-stroke engines. Mixture 1:50 (2%). To maximize the life of your trimmer, you may choose to use a high quality synthetic oil formulated for two-stroke engines. Mixture 1:50 (2%). Never use two--stroke oil intended for water-cooled outboard engines, sometimes referred to as outboard oil. Never use oil intended for four-stroke engines.
WARNING! Always ensure there is adequate ventilation when handling fuel.

1 gallon of premium fuel to 2.6 ounces 2-cycle oil. 2.6 ounce pre-measured containers are available at most chainsaw outlets.

You can find your manual here:
HusqvarnaUSA.com
http://www.husqvarna.com/us/homeowner/support/download-manuals/
Enter the 3 digit model number (no XPs, Es, just the numbers)
Serial number decode – useful when downloading IPLs and Manuals
06 1500198
06 = year produced – 2006 (single digit before 2000)
15 = week produced - March
00198 = 198th unit Husky produced that week
HTH
Lou