DR650SE Index Topic #10- CARBURETOR/INTAKE

Discussion in 'Thumpers' started by Krusty ..., Nov 8, 2010.

  1. Rumlover

    Rumlover Ed

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    There is no reason a well tuned DR/bst40 should not accelerate cleanly and fairly briskly to an indicated (stock speedo) 95 or even 100mph. It does start to flatten out around 90, but should still be moving up. Mine did it when stock at 4500'asl. Does it even better with some carb mods and improved gearing (14/43), and I weigh about 200lbs in my riding gear. I would look to fine tune the jetting a little more. Taping off the airbox some can give you an indication if you are lean or rich (if it runs better you are lean, worse you're rich).
    Good luck
    #41
  2. ER70S-2

    ER70S-2 Long timer

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    Thanks to the work of mx_rob. :beer

    [​IMG]
    #42
  3. basketcase

    basketcase lifelong reject fixer

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    Can someone help me with the basic steps in checking the float for proper adjustment, and then adjusting it as (if) needed?

    Thanks in advance,
    Rick
    #43
  4. ER70S-2

    ER70S-2 Long timer

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    Recently, I replaced the two o-rings on the float assembly. So, obviously, needed to check the float level. Manual says 14.7 + or - 1mm. Simple enough, turn the carb upside down and set the float level. Well, not really. Float level is supposed to be set with the float tab 'just' touching the needle valve. Inverting the carb 180* might compress the needle valve spring-----this isn't what they mean. Rotate the carb until the float tab contacts the pin in the needle valve, not 180* (upside down).

    Someone brought this up recently, and is when I re-read the manual. YMMV, etc. :freaky
    #44
  5. sagedrifter

    sagedrifter Southern Explorer

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    It does not have to be exact down to a pubic hair etc..... hence the +/- part.

    Put it on its side and the float should be parallel to the carb base... When you do that, its real close to .58".... :D
    #45
  6. eakins

    eakins Butler Maps

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    #46
  7. basketcase

    basketcase lifelong reject fixer

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    Thanks. That will get me close enough.

    :thumb
    #47
  8. davesupreme

    davesupreme grand poobah

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    'yer poppin' on decel cause' your pilot circuit is too lean.... pilot circuit is supposed to be about your first 1/8 of throttle. main jets really don't have anything to do w/decel popping.... you chop the throttle, close the butterfly, the engine goes lean as the high revs come down, and it pops.... i forget what pilot jet you said you have, but you may have to go a size bigger. try the pilot screw first, i dunno how your pilot screw works, some let in more air, some more fuel. whichever way, you need more fuel, and the popping will go away on decel. but.... at least in my KTM 450, too big a pilot, and it gets real hard to start when it's hot, floods real easy.... this is why the FCR's have a hot start circuit to let in more air.... on both my FCR and the kawi/keihin CV36's on my ZRX, the pilot screw lets in fuel, and screwing it out is richer.... get one of the aftermarked pilot screws that you can do w/your fingers, and adjust it as you ride around.....google pilot circuit and your carb type, and i bet you find alotta info....
    #48
  9. mcperformance

    mcperformance Been here awhile

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    Hi All, just reading some post & though I'd put my 2 bobs worths in.
    Everything you have done is all good. As I have done some dynos from stock Muffler - Modify Original Muffler (Still quiet runs much better) - Ground out inner weld on header (Improves a bit more over stock) - sports muffler (Baffle in & out) there are considerable increases that can be made over stock without breaking the bank, while still having reliablity.
    As you mentioned that you are happy with how the bike runs (not after WR 450 performance, if so get a different bike, expect to pay for it) then I suggest you do the inner weld mod as well.
    I'm looking at opening up my exhaust port only (Do it on the bike) as I can block it off safely. I'm only going to open it up at the very front to alloy it to breeze that little bit better & see what we end up with.
    Reason, being that to me the DR is a bike that is designed to run all day in stock trim (Realibility) but also has the protential to run much better with minor mods. (Very restricted bike in stock form)
    Thanks for your time, Interested in any feed back or PM me.
    Chappy.
    www.mcperformance.com.au


    #49
  10. NordieBoy

    NordieBoy Armature speller

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    Not sure who this is aimed at but the DR pops because the carb doesn't have an enrichener circuit.
    #50
  11. ER70S-2

    ER70S-2 Long timer

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    There is a cable adjuster for the throttle cable, up by the front brake master cylinder (more adjustment is available at the carb, if needed). The return cable needs to be adjusted at the carb and the gas tank will need to be off. Just press on the cables, like the arrows, and tighten until there is just a tiny bit of slack. I tighten my throttle until I can't hear the 'closed click' in the carb (not the throttle tube), then loosen a half turn or so.

    There must be a tiny bit of slack in both cables when you're done.
    Pic stolen from Wibby, post #1287 in the DR650 thread: :beer

    [​IMG]

    :eek1 :thumb
    #51
  12. ER70S-2

    ER70S-2 Long timer

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    Stock carb inlet fuel filter.

    Where is it? :scratch

    [​IMG]

    It's in there pretty snug, I used a dull shop knife to get it loose.
    [​IMG]

    [​IMG]

    This one has 28,000 miles and has never been cleaned. These dirt specks were invisible to my old eyes. :gerg
    [​IMG]
    #52
  13. eakins

    eakins Butler Maps

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    my IMS petcock > filter > oem carb (inlet in original position) setup.
    works great and i've gotten to 1/2" of fuel in the tank and zero flow issues (loop is not a problem).
    ziptied at the exit of the filter and wrapped around the carb inlet to keep the tube tight and back under the tank. inlet filter is gone. IMS petcock filter catches most of the debris and this filter gets the rest.
    IMS petcock works great, used washers on the tank bolts and snugged down the small philips when 1st installed. Haven't touched since, after 2+ years no issues. See no need to upgrade to raptor petcock.

    Attached Files:

    #53
  14. evilman

    evilman Been here awhile

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    http://www.ebay.com/itm/Mikuni-TM40-6-Carburetor-40mm-Carb-Honda-XR650-/170721575470?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item27bfcc822e

    Would this fit on the 05 DR650? This is much cheaper than Procycle TM-40
    #54
  15. tommybelvedere

    tommybelvedere Adv alacarte'

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    Heres what i have done to my 07 DR650 at 10000 miles did the air box mod, FMF Q2 Quiet version, 150 main jet from Procycle, Mixture screw adjustable at 1 1/2 turns out, KN airfilter with foam pre filter, 4th position on the clip, no extra hole for improved response.
    The results are alot more mid and low end range, it does have some light pops on deceleration but not to bad. I get 50-55 mpg and it is a blast to ride now, i have a hard time keeping a rear tire on it! It does every thing i ask it to has been very dependable. It will do 70 mph down the gravel or road fully loaded. I love this bike.:clap
    #55
  16. ER70S-2

    ER70S-2 Long timer

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    There's a flush brass cap on the stock set-up, easy to see with a mirror. When I did mine, I removed the carb, but left the throttle cables attached (seemed easiest). You'll have to loosen the two carb clamps to twist the carb so you can drill a small hole in the plug (1/8" or thereabouts). Remember that there are two hoses on the right side of the carb that fit tightly, they'll resist letting the carb twist and it seems the throttle cables also hit the frame backbone. That's why I pulled the carb loose. Once you have the pilot hole drilled, use a small self tapping screw to pull the plug. It isn't in there very tight, mine twisted a little when the bit grabbed. Go gently, the fuel screw is right under the plug, 3/16" maybe.

    If you want to remove the throttle cable bracket, those two screws were the tightest I've found on the DR, almost 'red Loctite' tight. If I didn't have an impact driver, they weren't coming out. Have two allen heads to replace them, for future ease of disassembly.

    Here's where to look:

    [​IMG]
    #56
  17. ER70S-2

    ER70S-2 Long timer

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    [​IMG]

    [​IMG]
    #57
  18. Nessman

    Nessman Evangelical Atheist

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    Here's mine...

    '05 DR650 goes like stink, makes me do stupid things and makes commuting a joy. Street only with Shinko 705s.

    I only get 30mpg and I'd like to fix that.

    What I have
    -Top cut out of airbox with foam filter
    -What appears to be the Dynojet needle with the clip just over halfway up.
    -42.5 idle, there's something before the 42.5 but I can't make out what it is.
    -160 main, just 160, no other markings.
    -Aftermarket longer mix screw out just over one turn.

    Is that a full DJ kit or bitsa?

    I know pop-a-wheelies out of corners and wannabe supermotoing don't help but they are fun....
    #58
  19. sagedrifter

    sagedrifter Southern Explorer

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    That's the usual set up for a free flowing exhaust.

    30 mpg is very bad. I would fix that now. Check your oil and make sure your not dumping fuel in the sump.

    Its probably a leaking petcock or dried out o-rings on the float. Maybe a worn float needle too.

    Procycle sells a refresh kit with the rubber parts.

    Float height needs to be .58" and make sure its all air inside. Old floats can leak and get heavy.

    I would guess its the o-rings.

    Sent from my GT-S5690L using Tapatalk 2
    #59
  20. Nessman

    Nessman Evangelical Atheist

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    Thanks Drifter.

    I've got a stock exhaust, what should my jetting be?

    It runs fat, no choke required at start so I think I'm fighting a jetting problem. No fuel in the oil and the float is high and dry.
    #60