Fuel Efficiency Questions???????

[wiese]

Just thinking of how to squeeze the must out of a Honda XR650R. But, this is not in regards to power; it is in regards to fuel efficiency.

So the question is: What can I do (besides listed below) to get the best mpg/kpl I can out of my bike?

I ride with fuel efficiency in mind.
I keep an eye on tire pressure for this reason as well. (If I have to be on pavement for more than a few miles I air up the tires even if I know I will be letting the pressure back out again)
I have already upgraded carburetors (which is supposed to added a few mpg/kpl).

Do aftermarket exhaust systems help with fuel efficiency or is the stock better? As for aftermarket exhaust systems what do I need to look for to increase fuel efficiency?

Take care and thanks for your thoughts
WIESE

[beddhist]

I think you already have the most important things covered.
Also, keep your engine tuned and your chain well lubricated.

A worn cam chain can also increase fuel consumption, as the valve timing gets retarded. Replace it if your consumption goes up and it's worn.

As engine and exhaust tuning is as much an art as a science I don't think there are guidelines on which system is more efficient than another, plus most people seem to have no interest in the subject. They only want more power and/or sound.

Wide luggage (ali panniers) and flapping clothing also increase consumption.

[oldbmw]

always keep awatchfull eye on you mileage. if it goes down that is always the first measurable thing to warn you that something is either failing, or off test.

[Frank Warner]

Originally Posted by wiese

I ride with fuel efficiency in mind.

Yes .. but how?

One way is to stop the throttle from opening by more that say 1/3 of full throttle... it is amazing how much that helps ... your accelleration will be a LOT slower .. but you will see the improvment..

[beat_]

you could change you final drive ratio to run at the same speed with les rpm
means biger front sprocket 1 maybe 2 tooths

i changed my rear sprocket from 45 to 43

[Wheelie]

Most after market upgrade parts, including exhaust, are designed to give increase in power, including most aftermarket exhausts. Also, messing with one bit of the engine while forgetting to adjust another (i.e., exhaust, bore, ignition timing, compression, carburation, etc), can give you all sorts of trouble, like running too lean or too rich, having your system sooted, overheating, inefficient fuel consumption, or other problems. Engine tuning should not be taken lightly by a novice as you really need to know what you are doing to be able to improve the characteristics in the way you want.

Aerodynamics have a fairly big impact on duel consumption, more so than weight loads, especially for lighter bikes. Tighter clothing, lower and narrower handlebars for a more tucked in riding position (uncomfortable), a lower seat for even less body exposure (more uncomfortable still), narrower panniers, etc. can make a significant difference... go on a diet, have somebody trim off your head and half your torso, and you would get great mileage...

Increased tyre pressure will also reduce your consumption a bit, as will sticking to the appropriate tyre for whatever surface you are riding on. Using a sand tire on the highway or a street tire on sand should be avoided if you want great mileage... anything that will make your bike roll with less strain will reduce fuel consumption is ofcourse what you will try to achieve .



Rather than spending time and money trying to alter the characteristics of the bike and the way you ride to save fuel, I'd recomend fitting a larger main tank or some sort of auxilary fuel system instead. An inexpensive spare fuel tank/jerry, can be fitted in many different locations on the bike, and can easily be integrated with your main tank using a 12V fuel pump and a switch. Or, if you want to go even cheaper and easier, just use a regular Jerry for those stretches where your original tank will not provide you with enough juice.