Motorcycle Repair: unleaded gaz on HD, leaded gas, test gas

Question
From Italy.
model FXST 1985
I start two years ago to use unleaded gaz , I notice a diffrence in the noise (higher)and some difficulies starting  the engine (problem to rev up,I have to wait few moment)Please, could you explain me what I have to do,if and how I have to change any regulation (anticipate or retardate tha spark)

Thanks  

Answer
Here in the US there is no difference between unleaded and leaded gas except for the fact that unleaded gas has no lead. The octane is still the same. Make sure you use high test gas in your bike. If your bike is pinging then you can retard the igition a little. When you say problems reving up, not sure what you mean. You didnt tell me how many miles are on the top end of the motor. It might need freshened up.
Good luck and happy riding
Mike