Hello, Assuming you have an electronic ignition, the timing is preset and requires no adjustment. If bike has been sitting for a long time, the carbs are probably gummed up. Take them apart and clean them thoroughly or have them cleaned professionally. What I found on my 550 is that the primary tubes that run to the bottom of the float bowls were plugged up as well as the tiny jets at the bottom of the bowl wells where the tubes go were plugged. These tubes and jets supply fuel from idle to 1/4 throttle and in my case the engine would not start or run below 3000 rpm. Clean these carefully with a small pin but do not damage or enlarge them.