I need mixture education!!!

[bigmak]

I have been seeing a steady decline in my gas mileage. As of my last tank, I was at 23mpg. The carbs have been cleaned, floats leveled, peashooter....you name it. I have told that I may be running too rich, and that I should adjust my mixture (which is currently at 2.5 turns out). Now, I'm not really sure how the mixture settings go, is it turn out to lean, turn in to richen, or vise versa?

I'm using a stock setup, with only an exhaust mod (drilled out). The carbs have recently been sync'd, and I ride moderately so I'm not sure why the crappy mileage? I also recently replaced my plugs, and pulled them today to see if they show signs of improper tuning, and they look fine. My last tank I got 69 miles when my light came on, took a little over 3 gallons to fill it back up. Anyone have suggestions on what could be the issue?

 

[113s&s]

in lean ...out rich... dont think that would be the gas milage problem 2 1/4 2 1/2 seems right to me

 

[maleko89]

I have been seeing a steady decline in my gas mileage. As of my last tank, I was at 23mpg. The carbs have been cleaned, floats leveled, peashooter....you name it. I have told that I may be running too rich, and that I should adjust my mixture (which is currently at 2.5 turns out). Now, I'm not really sure how the mixture settings go, is it turn out to lean, turn in to richen, or vise versa?

I'm using a stock setup, with only an exhaust mod (drilled out). The carbs have recently been sync'd, and I ride moderately so I'm not sure why the crappy mileage? I also recently replaced my plugs, and pulled them today to see if they show signs of improper tuning, and they look fine. My last tank I got 69 miles when my light came on, took a little over 3 gallons to fill it back up. Anyone have suggestions on what could be the issue?

How's your air filter?

Any fuel leaks?

 

[clintard]

you just have carb ghosts thats all, maleko will fix it!

 

[maleko89]

Clintard, I hope your hard drive crashes. lol

 

[82ndCowboy]

:rofl_200::rofl_200::rofl_200:

 

[bigmak]

No gas leaks, new air filter and fuel filter last month.

 

[clintard]

Clintard, I hope your hard drive crashes. lol

haha im sorry man i had to i dug that pic out the other day i had forgot all about it

BACK ON TRACK SORRY TO STEAL YOUR THREAD LOL

 

[maleko89]

No gas leaks, new air filter and fuel filter last month.

What is your float level set to? What about your plug gap? Since plugs are so cheap try replacing them and see what happens.

Here is an old post from Eric Harnish. It talks about fuel mileage.

Main jets have little or nothing to do with fuel mileage unless you are riding above 7500 rpm all of the time .
Fuel mileage is mainly a result of..... in order of importance
# 1 Float bowl fuel level...17mm...never over or higher than 16.5 mm
#2 Mixture screw settings... As lean as possible . Set up your carbs...then take a ride and adjusting each carb one at a time . With the engine at operating temperature Start with one carb and turn in the mixture screw a very very small amount at a time ....turn it in a hair..then ride it . Turn it in some more then ride on ....keep doing this until the carb starts to spit back when you accelerate or take off from a stop...then back out the screw a bit at a time till it stops spitting ....When done go to the next carb ....it takes a while to do this . I just carried a small screw driver in my pocket for a few rides and kept working with the screws . This is how we get over 40 mpg . When it is right the bike will be cold natured to start even in the middle of Summer and will idle smooth when warm . I always just smile when someone tells me how well their bike is in tune because it does not need the choke to start .
#3 Needle setting or depth and the condition of the needle and its receiving jet . Stock is stock....If your needles are adjustable then if ....White in color retainer ...1.5 to 2nd notch...beige in color 2.5 to 3 . is a good setting starting point with an open exhaust .
#4 Fresh spark plugs....use the stock plugs and change them at least every other oil change....I do mine every oil change ...They are cheap and the bike runs crisp
# 5 a good and perfect valve adjustment helps a lot too if they are out....it also makes tuning easier if all the cylinders are making equal pressure as a result of valve adjustment
As you can see....Main jets are not in the picture . If your main are Mikuni jets ....160 is way too big for your set up ....but if they are DynoJets they are just about right on .
With this set up you too can get over 40 mpg cruising at 80 mph + My bike with stg 7 got an average of between 130 to 140 miles to the red light all the time . Even hammering on it all the time in the mountains got well over a 100 miles to the light It is a matter of keeping it in tune .

Eric h

 

[Redbone]

Here is the text from Mark's previous post in case you cannot read it b/c of the black background like I use. I used red of course. :biglaugh: Or you can just highlight the text by using your mouse; left click the bottom right of the unreadable area and drag it to the top of the unreadable portion BAM! you can now read the text!
"Main jets have little or nothing to do with fuel mileage unless you are riding above 7500 rpm all of the time .
Fuel mileage is mainly a result of..... in order of importance
# 1 Float bowl fuel level...17mm...never over or higher than 16.5 mm
#2 Mixture screw settings... As lean as possible . Set up your carbs...then take a ride and adjusting each carb one at a time . With the engine at operating temperature Start with one carb and turn in the mixture screw a very very small amount at a time ....turn it in a hair..then ride it . Turn it in some more then ride on ....keep doing this until the carb starts to spit back when you accelerate or take off from a stop...then back out the screw a bit at a time till it stops spitting ....When done go to the next carb ....it takes a while to do this . I just carried a small screw driver in my pocket for a few rides and kept working with the screws . This is how we get over 40 mpg . When it is right the bike will be cold natured to start even in the middle of Summer and will idle smooth when warm . I always just smile when someone tells me how well their bike is in tune because it does not need the choke to start .
#3 Needle setting or depth and the condition of the needle and its receiving jet . Stock is stock....If your needles are adjustable then if ....White in color retainer ...1.5 to 2nd notch...beige in color 2.5 to 3 . is a good setting starting point with an open exhaust .
#4 Fresh spark plugs....use the stock plugs and change them at least every other oil change....I do mine every oil change ...They are cheap and the bike runs crisp
# 5 a good and perfect valve adjustment helps a lot too if they are out....it also makes tuning easier if all the cylinders are making equal pressure as a result of valve adjustment
As you can see....Main jets are not in the picture . If your main are Mikuni jets ....160 is way too big for your set up ....but if they are DynoJets they are just about right on .
With this set up you too can get over 40 mpg cruising at 80 mph + My bike with stg 7 got an average of between 130 to 140 miles to the red light all the time . Even hammering on it all the time in the mountains got well over a 100 miles to the light It is a matter of keeping it in tune ."