New set up , fine tuning

Discussion in 'Carb/Tuning' started by V4bandit, Jan 8, 2019.

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  1. Jan 8, 2019 #1

    V4bandit

    V4bandit

    V4bandit

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    Hey all! I just recently purchased the muscle jet kit from Sean. With reading every possible carb related thread with a bike near my elevation in Ontario, I've started with the following setup.
    155mains
    Pa1&2 stock
    Air corrector installed
    Stage7 needles, 3clip from blunt.
    Slides drilled
    Stock springs
    A/F @ 3 turns
    Float level set at 16mm dry
    Morley air box
    Dale Walker Holeshot exhaust

    Bike started right up. But had to run forever on choke, and occasionally puffing fire out the exhaust.
    Once warmed up seemed to run pretty decent.
    Synced the carbs and throttle response seems good. I'm unable to test ride until old man winter gives me a mild dry road day.
    Just wondering if there's anything I can do tuning wise on the lift, also what popping and fire out the exhaust means?

    Thanks
     
  2. Jan 8, 2019 #2

    one2dmax

    one2dmax

    one2dmax

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    Your float settings do have everything to do with the tune but sounds like you're where that needs to be. You can try to turn out the a/f mix screws a little bit and see if that improves it.
     
  3. Jan 8, 2019 #3

    caseyjones955

    caseyjones955

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    I sure dont know anything Sean doesnt, but I've read that stock springs and drilled slides do not play well together. I have no idea if that is the issue but it jumped out at me. I have the same jet kit and full exhaust, I think you will really like it. I hope you find the issue and get her sorted.
     
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  4. Jan 9, 2019 #4

    V4bandit

    V4bandit

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    Thanks Sean! I forgot to say I originally had the a/f at 2.5 turns and it just idled down until snuffed out. I turned it to 3 and it idle ok, once warmed up.

    I guess I’ll have to wait patiently now. Woke up this am to fresh layering of snow on the ground
     
  5. Jan 9, 2019 #5

    Fire-medic

    Fire-medic

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    If Sean recommended 155 Mikuni mains, then that's a good place to start. Pretty-sure 152.5 is the USA stock jetting spec unless you're at some high-altitude.

    You could always try tying-back a few coils of the stock slide springs to shorten them. I'm not sure what is the length of the Stage 7 Dynojet springs, other-than they're shorter than stock. Maybe a couple inches? That' and the larger holes drilled in-place of the stock small base-of-slides holes, should make them react quicker than stock.
     
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  6. Jan 10, 2019 #6

    one2dmax

    one2dmax

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    He may be a little fat with the 155's but each bike is different.
     
  7. Jan 10, 2019 #7

    Fire-medic

    Fire-medic

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    I've always heard, "better too-rich than too-lean," for engine longevity. Better safe than sorry.
     
  8. Jan 11, 2019 #8

    V4bandit

    V4bandit

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    I was going to keep the 152.5 main, but my plugs are ghost white, and I seen a few others running 155’s, so I thought I’d try it.
    I really have no clue haha, going off trial and error
    I wish I could ride it to find out, damn snow!
     
  9. Jan 11, 2019 #9

    caseyjones955

    caseyjones955

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    It was suggested to me to try main jets until I found the ones that pull the hardest at WOT and tune down from there. It's monotonous but I found it effective. Seans jumping off point for me was very close on all settings.
     
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  10. Mar 20, 2019 #10

    V4bandit

    V4bandit

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    So, I apologize for being quiet so long. We just broke out of the deep freeze here in Ontario.
    I was finally able to road test the Vmax after the Morley’s jet kit installed.
    I’m hoping someone with more carb knowledge can chime in.
    Starting off, it takes full choke and on for quite a while till warm.
    Once riding bike stumbles off line and surges around 3K. Above 3K to red line it pulls like a train!! Even in 5th gear will put the oil light on if I roll it open.
    Pulled the plugs and they are black ring with white electrode.

    Settings at- 155main
    Stage 7 needles with stock springs, 2nd clip.
    Slides drilled
    Air correctors and flat air filter
    3 turnsA/F screws out.
    Floats at 16mm (dry)
    Full Dale Walker exhaust

    Thanks
     
    Last edited: Mar 21, 2019
  11. Mar 21, 2019 #11

    veebooster

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    Don't get discouraged. You're closer to nailing it than you think. Patience is the key and one change at a time. I'm in southern ON and almost the same set up as you. 155 mains is right on. Try the dynojet springs. I used the 177.5 in PJ2. Mixture screws right around 3 turns 3rd clip on the needles.
     
  12. Mar 21, 2019 #12

    V4bandit

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    Thanks Veebooster! I’ll give the springs a shot, see what changes.
     
  13. Mar 22, 2019 #13

    Traumahawk

    Traumahawk

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    You have to run the Stage 7 springs. They are about 5 inches if i remember correctly, where as the stock springs are 7 inches....again if i remember correctly. i was always told, that you can run stage 7 springs without the slides drilled, BUT....if the slides are drilled then you MUST run the stage 7 springs. The stock springs, as well as longer, are stiffer. The drilled slides are pulling more air, and trying to pulling the slide open sooner, with the stock springs, trying to keep the slide closed longer. They will fight each other.
     
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  14. Mar 22, 2019 #14

    mabdcmb@yahoo.com

    mabdcmb@yahoo.com

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    The low end through 3K stumble should be cleared up with either the AF screws or needle. When you say surge, it makes me think lean. I'd try to shim the needle up a bit just to see if it helps move things in the right direction.

    Remember, 1 change at a time at this point. Take notes because its easy to forgot what helped and what didn't. To get near the magical 40mpg number you want things set as lean as you can while still running smoothly. It takes some time to dial it in.
     
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  15. Mar 24, 2019 #15

    V4bandit

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    Ok guys, I swapped in the stage 7 springs and went out again for another road test. It felt better in the mid but still something was off.
    I came back home and moved the clip on the needles from 2 to 3 clips from blunt. Went out again= she pulled hard right through, but slightly hiccups off idle. Pulled over and changed my A/F screws from 3 turns to 2 1/2 turns out.
    Now pulls like a gawd damn freight train, oil light glowing the whole time ! RPM range feels awesome, I might just leave it alone.
    Only thing in question is here is a picture of my spark plug. Does it still look lean, or is this ok to run? I’m not sure what my next move should be?

    Thanks
     

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  16. Mar 24, 2019 #16

    one2dmax

    one2dmax

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    You're not going to lean it up enough to hurt it (as long as you aren't running nitrous, supercharger, or turbo). It will just not run well if you get it too lean. If it pulls good and you're happy then stop and call it done!
     
  17. Mar 24, 2019 #17

    V4bandit

    V4bandit

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    Ok good to know.
    Thanks Sean
     
  18. Mar 25, 2019 #18

    Traumahawk

    Traumahawk

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    Lean is mean. if it pulls well, and you get great gas mileage, call it done.
     
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  19. Mar 25, 2019 #19

    Fire-medic

    Fire-medic

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    I bet dannymax and one2dmax will probably agree, turning the air fuel screws to a certain "2-1/2 turns out" position, for all-four, is really just a starting point.

    I adjust each screw to obtain the smoothest idle, in-turn, from that 2-1/2 turns out position. Or, as mentioned previously, popping from a pipe is usually due to leanness. Since you moved the clip, you may find that a bit of adjustment may get the bike to idle smoothly a bit lower, while still allowing good throttle response.
     
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  20. Mar 28, 2019 #20

    veebooster

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    Great job! Looks good to me. You're almost exact at my settings. If she runs great leave it as is.
     
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