Can anyone give me any clues as to why at one riding session,70,80 mph-mild acceleration,she would be getting 40 mpg.Then,on the next riding session,same circumstances-she would noticeable drop to like 34.9,35.0?Any thoughts on this?(she ended with 33 mpg)...so she could be dropping even more.Never had my bike behave this way.Air filter-new.What does this indicate ?Thanks all.

WOTheWATT did you actually do to the bike, blue? You have so much left to fill. Are we on a piggy? Do we have an OEM filter or aftermarket? Did we pull flies with body in bike or out of bike with throttle body on bench? What did you last do to have the bike start so strange? Do we have a clean ram air sensor? Is the ram chamber filled with oil?

If I rode the bike, had it for a day to duplicate, I would not need to know disshit. The bike speaks to me on start-up. So for us to figure this out... I need to literally know what the ufkc you did... YOu clustizzfulking blue in the face is now calm down, blue...... It's just a bike. You'll get it figured out eventually.

Haven't done anything to her.In 07-first thing-broke er in by the book.Next,removed flies,installed PCIII with the DJ map.She's run perfect ever since-EXCEPT.........As I said...I noticed one morning when I went out to start,she balked,cranked,then started,but the cold start function was not operating.Then the idle wouldn't stay level.Stock air filter(new).Had the mechanic prior to that all happening do a throttlebody sync.He changed plugs at the same time.When I got er back,there was no difference performance wise to how she was running before he did that stuff(she was running very good)Startups were fine.The ONLY thing I can think of is when I went to do the valve deal,and removed the throttlebodies.It had to be right after I reinstalled them that this began to occur.I wish I could remember how she was doing after the reinstall-but I think she was doing fine,otherwise,I would have been concerned.This "just started happening"about two,three weeks ago.I did nothing to my bike.Haven't "raced" her.Haven't blown any shifts.As I said,when I reinstalled the throttlebodies,I was very careful to not hit any screws,or adjust or move anything.Just slid her back in there and reconnected the stacks and all that.Checked all that last night-it's in there right,nothing messed up.Didn't remove the TPS's,I only unplugged them at the connectors when I removed the throttlebody.All the vacuum plugs are on there.Everything is connected.I pulled the flies like everyone else-on the bike-but again,that was in early 07,she 's NEVER had any issues starting.ALWAYS ran through the cold cycle.When she does start-she runs like she's doing the cold cycle thing-increased rpms.Then after a very short run of that,she drops down to "above"the set idle,and fluctuates up and down some.Then when I blip the throttle,as she's coming back down,she'll hesitate at about 200 or so rpm above the set point,hang there for a bit,then drop all the way down to the set point.Cables are adjusted correctly.My mechanic checked that.After hitting the set point,she idles rough,up and down-not EXTREME-but nothing like she should-smooth.(as she's always done).

* Last updated by: blue07 on 7/26/2009 @ 11:57 AM *

Air pressure is sensed by the MAP sensor and has a great effect on mixture. Engine temperature significantly affects the efficiency of the combustion. Humidity may also play with the compression, but not near as well as water injection would. If it was a closed loop system, fuel type would be a major factor especially the alcohol additive ratio.

Were you using the same fuel (as in same octane, brand, etc)?

How are you calculating your mpg? Manually, or reading off the dash?

I'm reading off the LCD screen.I could understand one or two,maybe even three miles per gallon drop(or increase).But this baby went from 36.7 to 41 mpg.And then again,she dropped (over two riding sessions with NO change in circumstances)to 33 mpg.Fuel is the same.

i wouldn't worry about it too much, i'm getting about 35mpg at the speed range that you mentioned earlier...a couple miles up or down here and there aint a big deal, when you see about 15 or more miles difference then you should get concerned about it...the way i look at it, i didn't buy a bike to worry about fuel economy, especially this beast

Fill the tank the same way all the time? I can at times get a little extra gas in it if I continue to fill when the neck show gas in it. Hard to explain, but there is a great air pocket under the last part of the top of the tank that may not get filled the same way each time you fill the tank. This in turn will give you mileage calculation differences.
And if the bike is leaning down on the front, the tank will fill even more than a level tank.

Normal riding I will get mid 30's. Before the break-in completed, I was averaging 30mpg.

With a four degree timing advance, high gearing, and lots of coasting and a sore left hand, I can average over 50mpg. I was able to reach 250 miles on a tank several times. RPM's kill gas mileage. This technique is what hybrids do.

there is a great air pocket under the last part of the top of the tank

I try to fill mine as much as possible and I get to 190 miles before my low fuel warning goes on. Also, I regularly get 38 to 39 mpg, no more and no less, unless I'm really "foolishly" riding the bike.

* Last updated by: extrapilot on 7/27/2009 @ 3:59 PM *

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