dave j wrote:
I checked a couple sites Cutomfighters.com and hubpages.com and they list fuel economy for a 99-2005 road star to be 35-39 MPG and Star motorcycles.com list 09 to be 36 MPG. So i'm guessing that anyone getting mid to high 40's is running extremly lean and hot as hell.


Not running lean at all and not even close to being lean. And I get 50mpg hwy and low 40's city. And backed up by air/fuel monitor. And I know others who have done the monitoring and get 50mpg and we are all the same AFR at cruise to get that mpg. Those sites mpg's are based on a carb that is tuned more for performance. There is no right or wrong. There is a spread in air/fuel ratio's where you can tune a carb without any issues to a bike engine. Ideal combustion is an AFR of 14.7:1 ratio. good for a liquid cooled engine, but will keep an air cooled engine towards the hot side, but even at 14.7, ya not gonna do any damage. I run my cruise speed at a 14:1 and get 50mpg, at a 13:1 I'm down to 40mpg. At WOT, I'm at 12.5:1 the richness to keep the engine cool and to prevent detonation. I use 65mph to check cruise mpg and do at least a 100 mile ride, same speed that Mikuni uses for their test purposes. I used the afr table from this site to tune carb, I did tune to the leaner side of the spread they show for each carb circuit to maintain the good mpg's: http://www.daytona-sensors.com/tech_tuning.html.