Sounds like you are on the right track there Vic.
Have you looked at your plugs lately? Because you are dropping your cruise RPMs significantly, you may be able to go to a hotter plug. The stock plug is a balance between low RPM and high RPM operation, and I bet you don't spend much time up top.
Because the majority of your riding is at low RPMs, I bet the stock plug is too cold for maximum efficiency in that range.
Here's a link with info about reading plugs for heat range and mixture -
Reading Spark Plugs Correctly
Jay