This is exactly the reason I signed up. My VR gets about 32-35 mpg but runs fine.  
I am going to change the diaphrams adjust the carbs and mess with the needle. I had he carbs rebuilt about a year ago no real gain. The blue beast runs rich puffing smoke when I throttle up, blowing black goo on the floor when i fire her up in the morning. 
    thanks Stu:thumbsup: