XL600r Dynojet Stage 2 Jet Kit

Discussion in 'Thumpers' started by KS-XL600, Jul 30, 2020.

  1. KS-XL600

    KS-XL600 n00b

    Jun 16, 2020
    Wichita, Kansas
    I used to have a "good" running '87 XL600r until I touched the carbs...

    I decided to tear it apart due to a broken kick starter spring along with a bad oil leak and carb leak. I had read lots of great things about the Sutton oil cooler, so to keep the engine temps down and extend the life of everything that heat affects I bought it too.(was really contemplating fabricating up my own JAGG cooler) But to add to that I thought it'd look really good with a repainted motor and the oil cooler brackets to match it.

    So the snowball effect happened and a leaky oil seal/carb and spring repair soon turned into upgrades like the Sutton oil cooler, repainting motor and brackets, the XR's only full exhaust system, and of course a Dynojet kit to re-tune the carbs lol.
    I suppose I can't complain about being a broke college student anymore if I make splurges like these.

    Now I have everything finished and am onto reinstalling the carbs. Although the exhaust has not come yet, so getting it running so I can dial it in once it does get delivered was my plan. But I have been having major troubles starting it, when it does run its extremely rich. I followed the instructions on the Dynojet kit packet given:

    1. Keep the stock main jet in the right (secondary) carb (is this specifying factory stock or the jet that I had in previously??)

    2. DJ128 jet in the left (primary) carb

    3. DJ124 and DJ132 as alternate main jets

    4. Install the DNO110 needles with the E-clips on the 1st groove.

    5. Set the air/fuel screw to the smoothest idle.

    Originally, I had a 62 pilot, 110 primary, 130 secondary with the no air box mod motor is stock to my knowledge. The Kansas elevation doesn’t change to much haha so right now I'm about at 1300’.

    I have now modified the Air box with the snorkel delete and put a Uni filter in. With an aftermarket exhaust pipe and factory header pipe as well as everything else. So per the DJ instructions I installed the needles to the 1st groove, 62 pilot, 128 primary, and 130 secondary. My air/fuel screw was out 1 rotation.

    This isn’t my first-time tuning carbs or working on my bike. And, the bike ran well before I tore it apart. But I’ve spent hours so far troubleshooting the Idle circuit, air/fuel mixture screw, pilot jet, float bowl level and needle valve. Then the electrical system to make sure I have sufficient spark to the plug as well as double checking my valve clearance. Although I have learned a lot digging into those things maybe I should have come here first.

    The one variable that I haven’t changed so far is the needles. It has been in the back of my head throughout the whole process, that I noticed the DJ needles are not only skinnier but also slightly shorter than the stock needles I had.

    And with having a shorter needle in the primary even on start up it will let a lot more fuel in. I have tried a smaller 58 pilot jet size and messing with the fuel screw. But it still seems to be getting way to much fuel.

    So, my questions for you guys:

    Does anyone know if it is typical for Dynojet's needles to be shorter than the stock needles?
    I have emailed Dynojet about this, will see what they say.

    -I could understand taper differences, but length?

    -Also, once I do get her started and begin messing with jetting and shimming the needles. What is a common setup for the dual carbs? Bigger mains on the primary or secondary?

    I’m thinking right now since I have the carbs out and apart again, I will try putting the stock needle only in the primary carb to see if she will start and idle correctly.
    But this is also weird, my rebuild kit needles both have different tapers. One has taper same as both stock needles, the other is larger.
    -Stock needles on the left
    -DJ needles middle
    -Rebuild kit right(thicker needle to the left)
    Needle options.jpg