Topic: MPG update -pods vs airbox

[hapsh]

I have been running my 550 with the stock airbox with a UNI element for about 5 weeks now after swapping from running UNI pods.  The bike definitely runs much better with the stock box especially low to midrange power, however I noticed that my MPG has dropped 6 miles per gallon since switching.  I have a very consistent commute that keeps my mileage within 1 mpg each fill up.  I was consistently getting 51-52 mpg with pods over a 2 month period.  As soon as I swapped over to the stock box with the UNI element I have now been getting 44-46 mpg.  The only other thing I changed was moving the jet needle clips back to the center position (stock) up from the 4th clip down.  The spark plugs look much the same, maybe slightly lighter in color but not too lean.  I also noticed that I need to use the choke much more/longer than with pods so I know I am running a bit leaner than with pods.  I am wondering if I am too far on the lean side which is making my engine power drop making it less efficient.  I may have to raise my jet needles back to the 4th position to see if that fixes it.  I am however surprised by this result.  I have gone over some other items to see if something else changed; tire pressure, dragging brakes, and drive chain lube, but everything looks good.  I know 46mpg is pretty good, however, I am on a quest to maximize MPG on my bikes.  My FZR gets 55mpg and I usually ride it harder and faster.

[crazypj]

On my 550f I was getting a regular 27mpg which went up to 41mpg when I fitted K&N filters and correctly jetted it.
 Never saw close to 50mpg.
 PJ

[Gordon]

That's why it's usually best to only make one change at a time.  That way when/if something goes wrong or you get an undesired effect, you know exactly what did it.  I'd suggest moving the needle clip back to where it was before the filter change and see what happens. 

[hapsh]

I actually ran the bike for a week with just the change of the airbox, but it felt like it was running a bit rich with a flat spot off idle with a small amount of "blubbers".  So I then made the needle clip adjustment and it ran much smoother.  My records show I got 48 mpg that week.  So it looks like I might have move the needle clip back and live with the "blubbers".  I could probably minimize the blubbers by leaning out the airscrew to compensate.  Its too bad though, the bike currently feels and sounds like it is in a state of very fine tune with super easy starting, smooth idle, and smooth power from the full range of throttle.  But a 10% decrease in MPG is pretty significant and hard to ignore. 

[BlindJoe]

How do your plugs look?

[TwoTired]

What exhaust do you have?  (I forget.)

[hapsh]

How do your plugs look?

They were a 15 with pods and are now more like 16 according to this chart http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

What exhaust do you have?  (I forget.)

Mac 4-1.  I also live at 2600 ft.

[eurban]

Has your gas station just started selling fuel with 10% ethanol?

[hapsh]

It has been 10% for at least a few years.

[nilsey]

i've been getting 35 city (lot of stop and go and traffic), 45 highway -- with k&n pods, 4 into two mac (leaky), 110 main jets (stock was 98), 1976 cb550k. 

[rbmgf7]

I had pods for the longest time and i knew i was getting sh*tty gas mileage. with 130 mains, my bike would suck up gas, literally.

i just now went back to a stock box with a K&N. WOW, what a world of difference. needs adjustment in the idle department and maybe change the needle setting or main size, but man does it run SMOOTH (currently on 115 mains). i had my pod setup perfected and it was alright all around but the airbox delivers such better throttle response. engine handes better in lower gears/RPMS. the only thing i miss is hearing the pipes roar after 5K with the pods. i guess you sacrifice MPG for coolness 

[gregimotis]

I have no idea what this thread is about.  I only clicked on it to stare at Hapsh' avatar.





now back to... whatever you were talking about.