The math for the front pulley :    23/25= .92   or 92%
   
                            60 mph =4008 rpm (stock)
                 (60 x66.8 =4008)

                            60 mph =4008 X.92 = 3687  (kawa front pulley)
                                Motor rpm reduced by 321 rpm @60 mph
                 (60 x61.456 = 3687)
     66.8 & 61.456 being the motor rpm to =1 mph  in each case (in 5th gear)  (4 speed bikes the number 66.12 stock-in 4th gear)
                 the 8 %  reduction in motor speed should show an ALMOST equal gain in mpg.
                   
                   

If you plan on any real distance riding, upgrade the rear shocks. Add a front mudflap.

   or use a Harley Sportster front fender,  It's  rear curves much nearer to the ground and keeps all road spray off your boots and shins.

Running too rich is bad, You can "wash" off the oil off the cylinder wall. causing wear.

In the 1960s there was a report in "Cycle"? magazine where they found out that most ring problems were caused by too rich a mixture.

If your oil smells gassy you are too rich. (or you haven't upgraded your petcock)  

WD wrote on 11/22/19 at 13:57:37:


It feels like the stock shock suffers at the start- especially when gunning around a tight corner, where the back end seems to squish and shift sideways; is that something I should expect to be confronted by a shock upgrade?

I'd like to keep myself as low as possible on the bike, often find myself crouched forward over the tank at high speeds  (70's-90's).  I removed the Boulevard-branded wind screen after 2k miles, and am mostly happier without it, will likely fit a very small cowling to deflect wind to the helmet, keeping cold air off the chest in the at-speed-position and supporting my head.   A hang glider pilot, I like to feel the wind.   I like the rumble and vibration of the bike.   These things let me know I'm not on the couch -that I'm alive, flying down the road, clutched atop a machine.

Dennisgb wrote on 11/22/19 at 21:44:49:
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As is rolling coal with a 4-stroke.  Watch a Pro Motocross or Supercross race (the all run 4-strokes these days) and you won't see a puff of smoke...ever.

Gary_in_NJ wrote on 06/19/21 at 11:59:08:
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They didn't when the first hit the scene (and they didn't smoke) and the system can be tuned with a computer/phone app.  They can make them as rich as they want, but they don't.  

My point is anyone saying the run rich enough to roll coal is talking silly.