My Husqvarna 125L trimmer makes a terrible grinding sound and vibration along the shaft. What is this?

SOURCE: WILL NOT START

This could help

http://www.fixya.com/support/t2241903-husqvarna_324ldx_4_cycle_string_trimmer

SOURCE: I have a husqvarna 125L gas trimmer and dies after

Could be clogged gas cap. Take the cap off and see if you can blow air through it. If no air passes, the trimmer will become vapor locked and wont be able to get enough gas.

SOURCE: hi im after the fuel mixture for a 125L husqvarna

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