the DR650 thread

Discussion in 'Thumpers' started by sleepywombat, May 1, 2006.

  1. TinkerinWstuff

    TinkerinWstuff Take it apart

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    He's saying theory is all well and good but none of us are aware of anyone who's used the stock needle IN CV carb WITH modified airbox AND achieved optimum results.

    let's see where it's been done successfully. Many of us here are well familiar with the practice of how to tune - especially procycle.
  2. procycle

    procycle Long timer

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    You keep saying how much better the OEM needle will work with an open airbox than the DynoJet needle. But you have no hands on experience tuning a DR650 with an open airbox.

    The problem with the OEM needle and open airbox is that the needle will have to be raised about 4-6mm to have any hope of running well enough to make the bike rideable in the mid-range. Raising the needle that much causes the beginning of the taper to rise out of the needle jet way too early causing a low end bog.

    In the real world the only viable solution available is the DynoJet needle.

    I'd like to see you show that there are other options and I've even offered to foot the bill to give you that chance.
    I'd also like to stop hearing about how much better OEM needle is until there is some proof to back it up.
  3. motolab

    motolab Long timer

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    He can speak for himself.

    If, however, you yourself are saying that none of you (who?) are aware of anyone who has used the stock needle with a modified airbox and achieved optimum results, I agree that with the USA needle, the possibility is slim (no need to shout BTW). If you are asserting that no one has used the non-USA stock needle with a modified airbox and achieved optimum results, then that's either because no one has tried, because whoever did try doesn't know how to tune, or because there is a better needle profile yet.
    Sure, let's!

    The point I have been trying to make is that, based on the chart I have posted several times now, the results when using the DJ needle can hardly be called optimal, and that experience with many different needle profiles (including many of my own) on many different motorcycles has shown me that a profile such as the DJ needle has is likely to produce a wonky CO trace such as the DJ needle does in fact in practice produce. The same experience has shown me that a shape more like the non-USA adjustable needle has will in fact flatten the CO trace vs. what a needle with a shape like the DJ produces. I suppose there is always the possibility of an anomaly, but I can't see how the non-USA adjustable needle would not be an improvement over the DJ.
    I think that depends on the definition of the phrase "familiar with the practice of how to tune". I'm not saying that to be rude. It's just that there are different levels of experience and different levels of tuning (some of which are equipment-dependent). Unfortunately there's no way around that.

    Regards,

    Derek
  4. barko1

    barko1 barko1

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  5. TinkerinWstuff

    TinkerinWstuff Take it apart

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    New topic anyone?

    [​IMG]
  6. Carl Childers

    Carl Childers Ghost in the Machine

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    My GSXR can showed up today so I pulled the stock exhaust off to get ready for the install and one of the first things I did was dremel out some of the weld out of the header pipe. I've gone from a trapazoidal opening to a round hole now that looks pretty good in comparison. I want to get the optimal opening without taking too much out so I was wondering if anyone could post a nice close up picture of the right amount of metal removal on this pipe?
  7. JTB488

    JTB488 Been here awhile

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    Mmmm, more power!!
  8. TinkerinWstuff

    TinkerinWstuff Take it apart

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    here's mine

    [​IMG]

    before - mine wasn't as ugly as some I've seen

    [​IMG]
  9. godaddygo

    godaddygo drdude

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    I would like to put a on-off switch for the headlight. Would still like it to work on high beam for flashing.
    I think the drawing says the white is for low beam...other two are yellow(high) and black/white I am thinking is the ground? I am thinking the switch on the white? But I am a electrical moron...
    Chris
    NorthernI daho
  10. victor441

    victor441 Long timer

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    It would be a good idea to add a relay and heavier wiring directly from the battery while you are at it (lights will be MUCH brighter), I did this to my bike per the sketch below using a switch and a standard SPDT headlight relay, however it is possible to leave the lights on and run the battery down this way
    OR, you could wire a relay and diodes so that the headlight is off until HB is switched on and then it is latched and works normally, only about $10 for parts, there was a clever DIY thread on this at http://www.advrider.com/forums/showthread.php?t=506789

    [​IMG]


    [​IMG]

    [​IMG]
  11. sandwash

    sandwash Long timer

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    Becarefull and not take too much off,it may crack around the joint.
  12. Carl Childers

    Carl Childers Ghost in the Machine

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    Thanks! Mine was even more restricted than your before shot. Judging by your after picture I think I'll stop where I'm at I've got it cleaned out to that point but don't want to weaken the joint.
  13. motolab

    motolab Long timer

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    Correct. And although it would be nice, I don't need it in order to know the trends.
    Are you saying that you tried a non-USA oem needle and raised it to its highest position by installing the clip in the lowest groove, and found the mixture to be too lean at 1/4 opening? If so, that's likely because the main jet was still too small. If the word mid-range does not mean 1/4 opening in this context, please clarify what it does mean. If you experimented with a USA needle instead of a non-USA needle, what method did you use to raise the needle?
    Again, if the correct size main jet is installed, the needle should not need to be raised much at all in order to achieve the correct mixture at 1/4 opening. You are right in that there is a definite tendency for certain rpm to become overly rich as a result of attempting to jet a CV carb for a modified airbox (the more it is modified, the stronger this tendency becomes). However it is the low to to low-mid rpm range that this invariably affects, and it's not due to having to raise the needle inordinately, but simply because of the large jump in main jet size that is required to get the proper mixture at the higher rpm. Couple that with a worn out emulsion tube and/or the float height being too low, and there will definitely be problems.
    I used to believe that needle shapes such as the DynoJet needle has would solve opened-up-air-box-with-main-jet-for-correct-higher-rpm-operation-induced low to mid-low rpm richness problems as well. In fact, my mind kept insisting that every instance where a needle shape like that didn't work had to be an anomaly, until it finally dawned on me that I had not ever seen one work, and that that leads to the inevitable conclusion that they don't work in general.
    I'd obviously like that too, but with how uncivilized your last few responses have been, I'm not sure I would want to interact on that kind of a level.
    We can easily turn that around. I have posted a chart with a CO trace that shows that the DynoJet needle doesn't work very well. You have not posted a chart with a CO trace that shows that the non-USA OEM needle doesn't work very well. Neither have you posted a chart with a CO trace that shows that the DynoJet needle does work well.

    Regards,

    Derek
  14. Chill

    Chill Been here awhile

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    I want to do something about the brakes on my bike. I don't feel that they are woefully inadequate, more that they could do with sharpening up a bit. The bike's only 4 years old but the brake fluid has never been changed (manual says should be every 2 years) and the fluid is quite dark which I understand is due to heat cycling/moisture absorption and not a great sign.

    So I'm thinking to change the fluid and while I'm at it upgrade to braided lines. If I go for new pads at the same time, what is the general consensus on this? Are OEM pads considered the best as seems to be the case often with bike parts or are EBC or after-market ones better? Will this give me the sharpening up that I'm looking for?
  15. procycle

    procycle Long timer

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    I don't know how you think I've been uncivilized. I mean really, we haven't even gotten down to shouting, name calling or even excessive exclamation points. :lol3 Maybe it's just because we disagree. Anyway, I have no animosity directed at you.

    A bunch of posts back neo1piv014 said he has an adjustable OEM needle and a modified airbox and hopes to end up with a good running bike. My best advice to him would be to not waste his time. Maybe with your guidance he can end up with a good result. I'll be very interested in seeing what happens. I don't mind being wrong if it means learning something new.

    We have different criteria for tuning. I'm really only interested in the end result. A bike should start easily, warm up in a reasonable amount of time (but not too quickly), have a stable idle, good throttle response, rev out cleanly, make the most top end power it can, not exhibit any hiccups, hesitations or bogging and get good fuel economy. If the jetting setup does all this it doesn't matter if the CO trace is flat, wavy, zigzag or loop-de-loop. If it runs within a certain range it won't cause any drivability problems and that's perfectly fine for bikes like the DR650 that will never be used as competitive race bikes. The DJ needle is far from ideal but it can be set up to satisfy all these criteria. There are thousands of DR650s out in the world that prove this is true. I don't have to look at a CO trace to be convinced. And I'll say again, the DJ needle best choice available until somebody comes up with something that actually works better.
  16. LucasLeader

    LucasLeader Been here awhile

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    As far as brake pads just don't get the Neutron brand that rockymountain sells. I put them on the rear and they were noticeably worse than the EBCs. I like the EBC Carbon X. I have them on one and a half of my bikes and they work great. http://www.ebcbrakes.com/motorcycle_brake/sintered_brake_pads/carbon_mx_tt_pads/index.shtml
  17. Adv Grifter

    Adv Grifter on the road o'dreams

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    New fluid is essential ... especially if you work your brakes hard in hot weather. I flush out old fluid for new about twice a year. Brake fluid absorbs moisture. Once every two years is NOT enough ... do it AT LEAST once a year.

    Pads
    You'll get different input on this.
    After I wore out the original Nissin stock brake pads I did what most everyone else does; I went with EBC sintered HH pads. (their best race pads) Cheaper than Nissin.
    I've run 2 sets of EBC fronts and 3 out back. At first I thought the EBC pads were OK ... but over time ... my braking was really not good. The EBC front pads were a bit worn, perhaps they were glazed? For laughs I swapped back in an old Nissin OEM set (quite worn but usable) back into the front brake. WOW! What a difference!

    Braking was instantly 20% better. I hunted around on line and found OEM Nissin HH pads for not much more than EBC pads. I'll never go back to EBC until they improve their HH sintered pads. BTW, I de-glazed my EBC pads ... not much improvement ... Nissin still much stronger.

    For more real world serious braking you could look into fitting a different caliper, bigger disc and different master cylinder. ALL these upgrades will transform braking power. It CAN be done. :deal

    PS: if your pads have ever been oil soaked ... then this could also be a problem and reason for Glazed pads. Fresh, clean pads essential.
  18. motolab

    motolab Long timer

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    I would never consider directing a phrase such as "put up or shut up" at anyone in a forum. I would not consider telling someone to stop posting about a particular subject matter either (unless it was off topic, in which case I would make a polite request).
    As you already know, my best advice for him is not to waste his time with the DJ needle.
    I don't think he'll need much, but if he does, I'll be available.
    I'm glad to hear that.
    I suppose you must be right about that.
    As am I.
    Unfortunately the shape of the CO trace indicates whether the criteria you set forth are being met or not.
    You left out that it should not be lean enough anywhere to cause detonation, and not be rich enough anywhere to cause excessive carbon deposits or wash the oil off of the cylinder wall.
    As the CO trace in the chart I posted shows, it will certainly not meet the not-be-lean-enough-anywhere-to-cause-detonation, and not-be rich-enough-anywhere-to-cause-excessive-carbon-deposits criteria. It may not meet the not washing the oil off of the cylinder wall criterion either.
    That they are out there with a DJ needle installed proves nothing more than the fact that there are DR650s with DJ needles installed.
    Interesting how I need to prove matters but you don't. In fact it seems that you don't have to answer any questions I ask you, or clarify anything I inquire about.
    That's already been done. Don't forget that needle shapes such as the DJ's exacerbate the very phenomena you claim they mitigate.

    Regards,

    Derek
  19. heirhead

    heirhead worlds worst mechanic

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    How bout those Lakers?

    Heirhead
  20. Magnum Noel

    Magnum Noel Been here awhile

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    Dear Procycle and motolab. I have a dyno jet needle and main jet with an opened air box and my bike runs like a charm with no detramental side affects that I can detect, Runs way better than it did in its standard configuration.
    Just my two bobs worth.

    regards Noel