How a needle and needle jet works on Mikuni carbs

แชร์
ฝัง
  • เผยแพร่เมื่อ 24 ธ.ค. 2024

ความคิดเห็น • 53

  • @shenaniganswhatsoever363
    @shenaniganswhatsoever363 3 ปีที่แล้ว +4

    Great info on the oversized main jet! I came to this conclusion on my last jetting endeavor. The needle taper and needle jet orifice is critical. I couldn't get my bike to clean out otherwise, even with the correct main jet at wot. I even suspected weak spark/ignition. I ended up trying 4 different needles, and quite a few needle jets, and finally got it. I would have saved alot of time with a sudco manual, I'll have to get one!

  • @RattlerSnake
    @RattlerSnake 3 ปีที่แล้ว +1

    Thank you sir. Helped me out in the first two min. Had no idea those manuals existed.

    • @junioraliados5985
      @junioraliados5985 2 ปีที่แล้ว +1

      Did you find the manual somewhere? I'm Brazilian and I haven't made mikuni carbs since 1999, but there are still some 2 strokes running and I really like working with them

  • @lennymorrison7291
    @lennymorrison7291 4 ปีที่แล้ว +4

    Thanks ,,, my question is should the needle touch the main jet nozzle when in off position, for no more fuel to enter .. can you please give explanation

    • @CAKEface75
      @CAKEface75 ปีที่แล้ว

      I'm wondering this too 🤔

  • @shanemyers4142
    @shanemyers4142 ปีที่แล้ว

    Love your vids brother. I'm having problems with mine. Cleaner than new and replaced all rubbers and nomore leak past the needle/seat. Its idling perfect, but dies upon throttle as if jets were clogged but arent. Dies on throttle every time unless I spray the carbs while it's running, then it'll rev normal and not die. I've done everything and just don't get it. All stock parts on the mikuni aswell.

  • @firebird14420
    @firebird14420 2 ปีที่แล้ว +1

    Would a bad needle cause gas in the diaphragm area where you take the cover off?

    • @aylorengineering.5513
      @aylorengineering.5513  2 ปีที่แล้ว +1

      I would say no, unless parts are missing from the needle assembly.

    • @firebird14420
      @firebird14420 2 ปีที่แล้ว

      @@aylorengineering.5513 thanks I think I found the problem or problems I'll know soon. For one the pilot jet I bought to rebuild was much thinner, longer, and a whole different tip than original even though a 35 size. 2 the fuel shut off valve was not working causing it to flood etc... I'll let you know if it fixes it. Thanks 👍

  • @tylercotugno8387
    @tylercotugno8387 3 ปีที่แล้ว +1

    Do the outside screws on the carb adjust the needle clip or do they adjust something different

  • @arthurleino
    @arthurleino 2 ปีที่แล้ว

    I have a 38 VM on my Shovelhead. This is a good video.

  • @lucasellyson6872
    @lucasellyson6872 4 ปีที่แล้ว +2

    Do needle and needle jets ever wear from old age rubbing against each other over time and possibly cause a rich condition? Thanks good explanation

    • @aylorengineering.5513
      @aylorengineering.5513  4 ปีที่แล้ว +1

      Yes they do. Especially on high vibration engines. But it does take time, the needles are anodized so are very hard for aluminum.

    • @dejonwelch
      @dejonwelch 3 ปีที่แล้ว

      @@aylorengineering.5513 I have a gx200 7.0 I installed my makini pz30 it wouldn't start up it had a lil gas in the carb can u give me some advice

  • @Kettenhund75
    @Kettenhund75 3 ปีที่แล้ว +1

    After watching this video I went and looked at my needle setting. Carb is a clone VM32 on a 2002 arctic cat 250 atv. The atv was bogging very badly right off idle (idles fine) and all the way through mid range. The needle clip was set to position 5. I moved it to position 1 with no change in the off idle and mid range bog/dying. Does that mean the needle and needle jet are too big?

    • @aylorengineering.5513
      @aylorengineering.5513  2 ปีที่แล้ว

      Sorry for the late reply, I hope you got it figured out. It's hare to tell a rich or lean condition with things being that for out. Testing is necessary, I would think the needle jet is too small.

  • @lucasellyson6872
    @lucasellyson6872 3 ปีที่แล้ว

    My SkiDoo 470 will idle fine, but i have to feather the throttle to get the RPMs up or it bogs and wants to die on take off. Suggestions? Thanks

  • @daveco1270
    @daveco1270 4 ปีที่แล้ว +1

    When they say to put the clip in position 1 is that the top setting? I haven't been able to figure out if settings 1 through 4 starts from the top and goes down or is the bottom setting #1? Thanks.

  • @averynguyen6296
    @averynguyen6296 2 ปีที่แล้ว

    my question is i thought that main keys controls the 80 percent to full throttle and needle jest controlled half like mid way throttle and pilot control idle and barley gas

  • @junioraliados5985
    @junioraliados5985 2 ปีที่แล้ว

    Hello brother, I'm Brazilian. I would like to know if I can get a manual on this subject? thanks in advance for your attention.

  • @christonechibinde6941
    @christonechibinde6941 3 หลายเดือนก่อน

    How can i access the manual?

  • @skyweapon
    @skyweapon ปีที่แล้ว

    thank you for a great explanation

  • @morgancure1604
    @morgancure1604 5 ปีที่แล้ว

    i just bought a new carb (keihen 38 a/s)...it idles nice blip the throttle sounds good,put under load and it takes off fine but seams to hesitate you push the throttle wot itll pick up and turn on....the plug color seems a lil bit dark but it doesn't foul plugs...really racking my brain trying to figure what my problem is would you know?

    • @aylorengineering.5513
      @aylorengineering.5513  5 ปีที่แล้ว

      So many factors to deal with tuning carbs. What motor, and where exactly is the hesitation throttle setting.

    • @morgancure1604
      @morgancure1604 5 ปีที่แล้ว

      @@aylorengineering.5513 trx 250r...has the esr 330 big bore...the hesitation comes a little past 1/4 to 1/2 throttle

    • @aylorengineering.5513
      @aylorengineering.5513  5 ปีที่แล้ว

      Then raise the needle. Tuning sometimes is just adjust and test. You are luck not having to do 3 carbs at a time!

  • @123lenny135
    @123lenny135 4 ปีที่แล้ว +2

    Nice explanation!!

  • @peter2ym8
    @peter2ym8 5 หลายเดือนก่อน

    Very useful! Thanks you!

  • @fatbob785
    @fatbob785 2 ปีที่แล้ว +1

    Thanks, that made a lot of sense 👍

  • @mikemaifeld6280
    @mikemaifeld6280 5 ปีที่แล้ว +2

    Is the stumble in the mid range generally a lean issue? With a bigger main jet, due to the needle not rising high enough to let more fuel in. would shimming fix it.

    • @aylorengineering.5513
      @aylorengineering.5513  5 ปีที่แล้ว +1

      A stumble is "usually" a rich condition. Lean get you that UUUUUHHH lack of throttle response. The main really has little to do with your midrange.

    • @mikemaifeld6280
      @mikemaifeld6280 5 ปีที่แล้ว +1

      Yes my midrange is blaaa then picks up. I have a 4 into 1 header and Pods air filters I upped the main jet I think the next above 110. So I'm thinking I need to raise the needle jet. I have 3 tiny washers on there now replacing the stock plastic washer. I have a 1980 Suzuki GS1000 BS34 carbs. Dang can't remember the size of the main jets. should have wrote it down. thanks

  • @bazrazin1
    @bazrazin1 3 ปีที่แล้ว

    why is the pilot jet higher than main jet.

  • @Closdmon
    @Closdmon 3 ปีที่แล้ว +1

    Good stuff please make more on a tm-40 please!

    • @aylorengineering.5513
      @aylorengineering.5513  3 ปีที่แล้ว

      Sorry, I have never messed with the TM 40s. But, you can get the Sudco mikuni carb manual which will probably answer all your questions.

  • @tehpepper78
    @tehpepper78 9 หลายเดือนก่อน

    Thank you for the video.

  • @dylanbradley6213
    @dylanbradley6213 3 ปีที่แล้ว

    He kinda correct but he left something out the e clip can be adjust down the needle in the slots for more fuel or up the needle for less fuel, so if are jetting the carb you probably should have the needle valve in the lean or less fuel position until you have done the jetting then move e clip down by one slot at a time for more fuel again

  • @Bass.Player
    @Bass.Player ปีที่แล้ว

    Nothing about part throttle?

  • @johnnyrebellion8672
    @johnnyrebellion8672 ปีที่แล้ว

    I will never understand the complexities of a carb. It's like a swiss watch. I just had my ECU reprogrammed for my 2022 GasGas. Very happy. The TM-33 on my DR350SE on the other hand...

  • @250race
    @250race 5 ปีที่แล้ว

    You said that right on.

  • @leandramartinleatherdesigns
    @leandramartinleatherdesigns 3 ปีที่แล้ว

    great info!! thanks

  • @tarunk04
    @tarunk04 2 หลายเดือนก่อน

    👍😎

  • @mrandrewdennis1
    @mrandrewdennis1 2 ปีที่แล้ว

    Great content thank yoi

  • @mcdk72
    @mcdk72 5 ปีที่แล้ว +1

    Nice!! Thanks.

  • @michaelbennett9738
    @michaelbennett9738 5 ปีที่แล้ว +1

    Good video sir

  • @stevethomas7463
    @stevethomas7463 3 ปีที่แล้ว +1

    Clear as mud. Manual says never drill out jets.

  • @justinbrents3110
    @justinbrents3110 8 หลายเดือนก่อน

    ❤😂

  • @franksavignac2788
    @franksavignac2788 2 ปีที่แล้ว

    i have bandit 1200 2005. i installed exhaust and 2mm bigger air intake box hole.. I already drill my Main jet to 110 and a lill on pilot jet also.. i got it good. bike run well but.. past 7000rpm i get RICH 11.6:1AFR everybody sayd... reduce your main jets.. so i made my calculation and went for 105 main instead of 110... Yesss my TOP END 8 9 10k rpm is good now 13.0:1 But All my mid range 1/2 throttle 3/4 DONT ANSWER anymore.. LEAN LEAN as fuck.. YES CHANGING MAIN JETS i LEAN mid range And top end WOT of course.
    so i raise the needle.. it did fuck all. I reinstalled the 110 jets. the bike run so good now.. But rich past 7000rpm at WOT

  • @choppergirl
    @choppergirl 9 หลายเดือนก่อน

    These carbs get clogged up and fail so often and cause everybody a world of grief, I wish I could just change everything I have to fuel injectors and a fuel map. I don't know why we are still using 1880's technology in 2024.