I replaced my flasher unit with one for LEDs saves using resistors, most auto part stores like Halfords should carry them , take your old unit in with you
What i used to do when LED 1st hit the streets and the compatible flasher units where not readily available was to fit a hidden "slave bulb" in line which loaded up the flasher unit and kept its normal flash times..A hidden bulb in a standed holder could go behind the side panels or if you have Ramair you could fit it in the original filter box....A cheap fix and even cheaper than a couple of load resistors
Cant look it up at the moment but that one is is the wrong one - linked is the cf13JL-02
What is required is cf13GL-02
MUCH easier & neater than messing with resistors - simple plug n play to swap out
Here's one source I found in Search in UK- you might find it cheaper if you search Ebay or amazon
I had integrated LED indicators on my tiger 1050 without any resistors. Flashed a bit quicker but not quick enough to fail MOT. So I assume sometimes they might not be needed at all.