LC4 Adv. normal fuel range...?

Discussion in 'Thumpers' started by Doc_Busa, Dec 22, 2005.

  1. Doc_Busa

    Doc_Busa Been here awhile

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    Hey guys, can you chime in on how far your LC4 Adv. will go on a full tank of fuel? I am trying to figure this out "the easy way".

    I seem to be getting around 250 miles on my '03 with the normal mods and pretty high-speed riding (several trips to work on the freeway), around this mileage the fuel warning light kicks on... from two past experiences, it seems like the yellow light comes on pretty close to my need to flip the reserve switch, and then I only get a few miles before she's dry. Now, I have really only done this experiment twice, and only once since the new jetting/exhaust. Tonight the yellow light came on with 255 miles on the ODO.

    Thanks!
    #1
  2. creeper

    creeper Still alive...

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    A little tidbit of information for you Doc...

    I just happen to have my tank stripped of hardware, including the main fuel valve.

    As you can see in the photo, the hard standpipe for the primary valve is 5.0" in length. This gives you a better idea of the amount of fuel you potentially have remaining in the tank. So if anything, your light is coming on a little late.:D

    [​IMG]

    Oh yeah... I get about what you get for mileage under the same conditions, but I can go about 30 miles after the light comes on.

    C
    #2
  3. Doc_Busa

    Doc_Busa Been here awhile

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    Thanks Creeper, somehow I knew you would be the first to answer :evil

    Sounds like things are on par. How many gallons does she hold again?
    #3
  4. gybeman

    gybeman Been here awhile

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    27 or 28 litres (its been debated) or roughly just under 7.5US gallons.
    #4
  5. BlitzBike

    BlitzBike LC4 Pilot

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    I'm consistently getting 225 Miles with an FCR 168 main 48 pilot and side airbox intake.
    Thats primarily 85+ miles an hour highway commute with 17/42 gearing.
    #5
  6. meat popsicle

    meat popsicle Ignostic

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    250 miles / 7 gallons ~ 35 mpg... not heinous, but I think it sucks when the F650 gets over 50 mpg, which would translate into another 100 miles on a tank for us! That is why once I get the quiet core in my can, and a bit of dough, I am having Scuderia dyno for efficiency. I am sure the power will still be sufficient. I have no self-esteem issues... :smooch

    I get about the same range on my 03. Hey creeper, could the high flow head have a significant effect on mpg? And is the power so much lower on the pre-HF that it was a good trade off? Maybe I need to trade someone for a low flow head? :amazon

    ps - I got 25 miles on reserve; the bike died pulling into my driveway... :D Then I pushed it almost 10 blocks to the station the next day.
    #6
  7. ChrisC

    ChrisC Amal sex?

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    OK all of you overjetted underachievers... I get around 300-315 miles before reserve. Stock jetting, racing sidecover, and IDS2 Quiet w/10 discs.... But don't forget, I ride like an old woman :cry
    #7
  8. Doc_Busa

    Doc_Busa Been here awhile

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    I am surpised the mileage is not higher too. Again, I am flying down the highway, then ripping it for a mile on a trail I discovered, each day (two times a day). So, it sounds like it is normal. I actually get better mileage on the BMW GS, but it is fuel injected and more importantly, it has a 6-speed tranny.

    I still prefer to commute on the KTM just because of that little trail I found... FUN!
    #8
  9. creeper

    creeper Still alive...

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    I actually get around 43-47 mpg when just cruising down the road at a steady speed... which is a rare thing. It's not like I bought a KTfreakin'M for fuel economy.
    If I were to figure a grand average... it'd be somewhere in the neighborhood of 40 mpg.
    Workin' the throttle and keepin' it spinin' in the 5K to 7K range really puts a dent in the ol' fuel economy.
    I bet if you jacked up the air pressure, ran a 17/40 gear set and didn't go over 60 mph, you'd get way over 50 mpg... but where's the fun in that? :D

    The term is "adult ridden" my darling. :smooch
    #9
  10. meat popsicle

    meat popsicle Ignostic

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    True, and I bet that blitzbike's 168mj don't help none either... But if I switched to the pre-03 Low Flow head, would I see much of a change in range, all other things being equal?

    "AARP Certified Rider" :jose
    #10
  11. ChrisC

    ChrisC Amal sex?

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    [​IMG]
    WHOOOOOOOHOOOOO!
    #11
  12. creeper

    creeper Still alive...

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    I happen to have a pre high flow on the shelf... wana' find out? :evil
    #12
  13. meat popsicle

    meat popsicle Ignostic

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    I knew that was coming... swap a very lightly used 03 High Flow for a blueprinted pre-03 Low Flow? Hmmm...

    [​IMG]
    :evil
    #13
  14. creeper

    creeper Still alive...

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    It's nice of you to post a photo of my porting crew... they work so hard, and deserve a bit of recognition. :D
    #14
  15. meat popsicle

    meat popsicle Ignostic

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    :zilla
    #15
  16. markjenn

    markjenn Long timer

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    Just to add some confusion to this thread, many readers on this site are running some very rich jetting which doesn't help mileage. I'm running a 152.5 or 155 (forget which) but a lot of folks seem to like 165+, along with richer needles, slow jets, and idle jets. I pretty consistently get 40+ and if I ever did steady/reasonable speeds, I expect it would get 50. (There is little rhyme/reason to bike fuel mileage - I have a barn-door faired, shaft-drive, 1300cc inline-four sport-touring bike that gets about the same.)

    Second, the confusion over tank capacities is not just 27L and 28 - late bikes list 25 on their spec sheets.

    Finally, the early bikes (at least the 2000 I have) have no low fuel warning light and dual reserves - the standpipe on the left and a thumbscrew petcock on the right. So the only way to get full reserve is to switch the left petcock and open the right valve.

    Finally, finally, a few of us have reported that some bikes won't restart while on reserve and the KTM OM mentions this. So running the bike on the last gallon or so of fuel may be sketchy.

    If you anticipate running a 640 Adventure in marginal fuel situations, this is definitely one where you probably need to do your own testing, especially with the oddball changes over the years.

    - Mark
    #16
  17. bikemoto

    bikemoto Tyre critic

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    My 2005 model is listed as 25.5L tank with 3.5L reserve. Still completely stock except for Emig lowering links and Symtec grip heaters.

    I don't know about full capacity, haven't yet measured it.

    However, I did drain the tank to reserve, then drained reserve to measure it... all of 2.5L. There was 0.3L left in the tank that wouldn't come out. This was with the bike on the centre stand in the garage. This seems too little; I am keen to increase the length of the primary intake pipe to allocate more fuel to reserve.

    [Edit]
    I stuffed up!! :eek1 When I drained the tank, the bike was on the centrestand, but in a nose-down position since I've pulled the forks through 25mm to match the Emig lowering links. I've repeated the measurement with 25mm stacked under the front tyre to correct the bike's attitude, and the reserve this time is 3.8L...much better.:clap That means a range of 65-87km on reserve, calculated from my worst/best recorded fuel economy.
    [/Edit]

    On-road, the fuel warning light will come on up to 10km before reserve is required, so I usually change over as soon as the light comes on, as it can take some time to refill the carby.

    On a steady 100km/h cruise on-road it returns 4.4L/100km, that is, 580km for the tank. This would not be typical usage! But does show that it can be pretty economical if required.

    More typical would be the 5.5L/100km or 460km for a tank. That was returned over 850km of mainly 4wd trail usage and some two-up road fanging.

    Yes, this thing pops on the overrun and is a pig to keep idling when cold.
    One day I'll get around to playing with the jetting...
    #17
  18. DC950

    DC950 Microadventurer

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    I also have a 2000 and agree with everything Mark said. I have the same main jetting (forget which!) and a stock needle raised one notch. I get 50-52.5 mpg at 60-65mph.

    When I have had to switch to the "right side reserve" on my bike, 3 out of 4 times I had to lean the bike over as far to the left as I could get it without dropping it to get some fuel over from the right side. It also seems the only way to get it started is to turn the left petcock "off".

    You are probably better off opening the right side thumb screw petock reserve as soon as you switch over to reserve with the left side petcock. Perhaps then you can get the fuel to pump or splash over.

    Even flogging my bike on the Fall Color Tour I got over 40 mpg. I've decided the last bit of fuel on the right side is best used to start a campfire while I wait for help.
    #18
  19. meat popsicle

    meat popsicle Ignostic

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    as dc950 alludes to below, you can shut off the right side crossover valve after fillup and use that to extend your reserve. it's capacity will depend upon how often or when you crash and/or how much you lean and bang around (splash) but it will hold a touch more. do your test again and let us know how much extra it holds in the shop (max).
    #19
  20. Velocibiker

    Velocibiker Adventure Antagonist

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    Just to add to the confusion :wink:

    I get about the same (indicated) milage as you do Doc. I have an '02, 11 disks in the 'trapp and running a 160 main jet. I usually have the Givi cases hanging on and I weigh about 230#. My commute consists mostly of a highway run from Summerlin to Boulder Hwy. Some surface streets, but only a couple miles. Even if I'm out trail riding, I seem to get the same number of miles per tank.

    Now - what do you have your tire size set at? 19 or 21? I've heard through the rumor mill (here) that if you're set at 19, the speed is correct but your distance is off. If you're at 21, the speed is off, but the distance is correct. I can only confirm the speed as I've verified it against my GPS. Haven't ever needed to know exact distances, so can't confirm or deny that part.

    If it IS true that a wheel size of 19 screws up distance, than we could be getting much different miles per gallon ratings.

    Finally, when my yellow low fuel light starts blinking, I can only go a couple miles before the bike starts to die. If I get to a gas station right away after switching to reserve, I can pour about 5 gallons in. That gives me (supposedly) 2.2 gallons in reserve. I've never completely drained my tank and then filled it to the brim to see what the true total volume is. I'm sticking to the assumption that I have a 7.2 gallon tank :D
    #20