I know the old air cooled V twins used to run the rear cylinder on a slightly different fuel ratio due to the heat. But the strom should not need this, the balance is way off once the throttle is opened.
Checked this cos I am getting a lot of con rod noise under load, off load, over run and idle are all smooth and quiet.
My old K6 SV650 at 35K was so quiet it makes this 11K strom sound like it has been to the moon and back.