136.5 mpg on my Yamaha C3
 

I purchased a 2007 Yamaha C3 scooter last fall and have been experimenting with different tire pressures, riding habits, and various things and have so far managed a best average of 136.5 mpg. I'm super excited about having triple digit fuel economy, especially with so little effort. I run the tires at 40 psi and have found that the best thing to do is just run it as close to 40 mph (the limit of the speedometer) as possible, and shut if off at stop lights (engine off coasting isn't really very helpful, since it has a CVT with no neutral, though I do shut off the engine while coasting). It's a hoot to drive and I can commute to work and back all week on less than a gallon of gas.

This is my first post on this forum and I'm glad I joined. I really enjoy reading about other people's projects.

The only thing i would be concerned with is shuting off the engine while moving. I don't know anything about CVT's but I would think it needs to be lubricated while moving

CVTs on scooters are purely mechanical, using a rubber belt and weights that slide along a ramp as centrifugal force is applied. No lubrication needed. Plus, because there is no neutral, the engine is turning with the transmission; turning the engine "off" while moving really only serves to kill the fuel pump so that the injector isn't being supplied with fuel while decelerating (the C3 is fuel injected). As long as the engine is turning over, the oil pump continues to operate, it's just not being powered by gasoline but rather by the rotation of the rear tire as you decelerate. So, even if the transmission required lubrication, it would be able to get it.

The 50cc engine and some improved aerodynamics could approach 200 mpg.

Maybe not with a CVT wich is one of the less efficient means of transmiting power ...

I went from a Helix to a GN to gain 10% of FE.
Same capacity, same use ...

I also have an '07 C3. New air filter, synthetic Mobil 1 oil and now a new back tire that I can run at 40 PSI (purchased today). Lessee what she'll do!

http://i1187.photobucket.com/albums/...connor/121.jpg
Some discussions on the scooter aerodynamics lead to this sketch of a body for my Honda Elite project some day.

Try seeing if they have a set of Dr. Pulley sliding roller weights that fit your bike. Should help even more

Nice numbers.

You should try full throttle while engine off coasting, that should help you "coast" farther by reducing pumping losses