If I understand correctly, to get peak mpg, set up your gearing to operate at peak torque at the desired speed.

Looking at that DYNO sheet....no wonder I love this bike.  The maximum torque value is almost constant between 3,000 and 5,000 rpm.  This makes for a nice comfortable ride on the back roads without making lots of gear changes along the way.

The engine will never make a lot of HP as the rpm is limited by the long stroke.  Engine improvements should be made to increase the torque values - which will allow the engine to pull harder and pull some taller gearing.  My bike has a Wiseco 95mm, Stage 1 cam, Mikuni carb and the double Kawasaki pulley conversion and an 18" rear wheel.  It is a Cafe' conversion and does not have a windshield or saddlebags, and it can pull 5th gear easily with the taller gearing.  I do not shift into 5th gear at speeds less than 60mph, and at 70 mph the engine is turning 3,925 rpm according to the chart Serowbot prepared.  It will pull 5th gear to a speed somewhere around 85mph before the air resistance wins the battle.  For higher speeds I need to shift into 4th gear.

Doing engine modifications with the stock gearing will allow you to accelerate faster, the Wiseco will make your engine more efficient and can increase your fuel mileage a bit (at the expense of using premium fuel), cam changes most likely will reduce your mileage a bit.  If you have a windshield, saddlebags or are a "plus size" rider.....try the front Kawasaki pulley change first.  I am not sure how well the double Kawasaki pulley conversion would work with a windshield as you are pushing a lot of wind out of the way.....although the difference may not be all that much as you would be pushing the wind out of the way with your body anyhow.

Should you tear a good running stock motor down to make these improvements.......that is a hard decision to make.  Gearing and engine changes can make 70 mph much nicer - but it is a lot of work and is pretty expensive.  In some instances you may be paying as much for the engine upgrades as you paid for the bike.    

I got some of my parts from Lancer, some on eBay, and some by sending my cam directly to Webcam.

The stock clutch appear to be adequate...provided that you have not polluted it with oil that has any friction modifiers and wait until the engine and oil is fully warmed up before you do any full throttle acceleration.

With the work you are planning....you need a little bit of work on the exhaust port to smooth the flow and eliminate a portion of the restricting doughnut.

I am scared to add it all up.  One of the scariest things is that I spent close to $ 200 just on gaskets, oil seals and bearings.

I have the records at the office and can get a ball park - but I suspect I am well on my way to $ 1,500!  I did get some of that back as I sold the low mileage piston and cylinder on eBay.

Iceman4193 wrote on 06/30/15 at 19:58:38:


No....closer to $ 100.  But I needed new crank and balancing shaft bearings.  Then when you add new seals for the pulley, right crank, shifter, valves.....and all those little sealing washers for the cylinder head cover and right engine cover......and you need to buy a new Head Plug so that doesn't leak (new Verslagen one)......and then you need to buy a new tube of Suzuki Bond....and it all adds up.


UPDATE:  I was pretty close with my $ 1,500 guess.  I just looked at my invoices and the right crank bearing was $ 75.41 alone and I have close to $100 for the crank bearings!  The total is about $ 1,400 without the muffler change.  Webcam recommends hardwelding the rockers so I did it.....from what I understand the stock rockers work fine with the Webcam.

BEARINGS, SEALS, GASKETS, LOCK WASHER FOR PULLEY   $ 326.32
CAM SENT DIRECTLY TO WEB CAM,                                     $ 155.00
HARDWELD ROCKERS (PROBABLY NOT REQUIRED)             $ 190.00
WISECO 95MM PISTON                                                       $ 149.95
BORE AND SILICONE CARBIDE COATING ON CYLINDER       $ 165.00
MIKUNI CARB KIT                                                                 $ 389.00
UNI FOAM AIR FILTER                                                           $  18.99

                               

Why so much for the Mikuni carb?

Also, can you explain "hard weld rockers"?

Thank you for the info. Bought my wife a 2007 to learn on last week and I am already planning on her either wanting more out of the bike or switching to something bigger when she gets comfortable. If she switches, I plan on turning it into a project bike.