Visable dirt in the fuel line means dirt in the carby so it will require a strip and clean or a replacement carby.
You can always try one of these but they can be a bit of pot luck.
https://www.ebay.com.au/itm/Carbure...UMK425-Trimmer-Bush-Cutter/123164046704?

Last edited by NormK; 18/10/19 05:40 PM.