Carby Need Help with Carb Identification

Discussion in '2-Stroke Engines' started by Daniel_62, Jul 21, 2011.

  1. Daniel_62

    Daniel_62 Member

    trying to ID this Carb, After reading all this & that on different set ups I am confuzed! I see alot of different carbs for sale on the Websites & Ebay

    I have a new Skyhawk GT 5 66cc dated 09-10-09

    the carb has :
    a petcock
    tiny little choke lever
    On left side it has little pump plunger
    and 1 Air mixture screw, (or is it an idle adjustment)

    thank you

    David
     

  2. motorpsycho

    motorpsycho Active Member

    you probably have an n.t. carb. that came on almost all happy time engines for a long time. A lot of them now come with cns style carbs, which can be a real hassle to get tuned right.
    Yes the screw is for idle adjustment, these n.t. carbs do not have an air-fuel adjustment screw.
    The petcock is a secondary fuel shut off built into the carb.
    The plunger is a "tickler" button, and it's like a primer button (like you'd find on most weedeaters and chain saws).
    If you had a picture of the carb, it would be really simple for someone to identify it.
     
  3. DuctTapedGoat

    DuctTapedGoat Member

    What kind of air filter is on it?

    If it's a black rectangle, it'll be a CNS.
    If it's a red rectangle, it'll be NT Speed.
     
  4. Daniel_62

    Daniel_62 Member

    Its the red one

    David
     
  5. DuctTapedGoat

    DuctTapedGoat Member

    There are two carbs with the red cover - there is the NT Speed, which has one screw on the side and one cable coming out the top, and there is the CNSv2/GenB which has two screws on the side and two cables coming out the top.
     
  6. Daniel_62

    Daniel_62 Member

    Thank you for the verification, I do have the NT 1 screw, 1 cable

    It started last night and ran for the first time.

    Idles well, No hesitation, decent throttle response, I do have a Single Boost Bottle Kit
    But not installed Yet

    Using a 16: 1 mix right now

    Is there a More preferred Carb for future use? Better performance?

    thank you DuctTapedGoat

    David
     
  7. DuctTapedGoat

    DuctTapedGoat Member

    For stock carbs, you've got the best one out there (when compared to CNS, CNSv2/GenB, NT).

    ThatsDax.com sells a Dellorto clone for 30-40 bucks, I hear NOTHING but great things about it. It's second only to a real Dellorto.
     
  8. darwin

    darwin Well-Known Member

    Dunno its looks just like a carb to me.:idea:
     
  9. motorpsycho

    motorpsycho Active Member

    If you take the time and tune the nt carbs, they will always perform well.
    Once you get the jetting sorted out, the float level set right, and get the jet needle clip set on the right slot, your engine will run really good.
    The nt carb really isn't a performance carb, but tuned right, it can be very reliable and give your engine decent power.
    Going to a cns can be nothing but a headache.
    they can be difficult to tune, the choke works opposite of a standard choke, and sometimes the cns carbs don't stay attached to the intake manifold.
    I had a cns for 1 day, and went back to the nt because no matter what i did, i could not get the cns to run right at all.
    I've re-jetted my nt carb which was a lot of trial and error, and getting the jet needle in the right position takes some time as well.
     
  10. Big Red

    Big Red Active Member

    4-Stroking

    Hey Moto,
    I've been all over trying to find the best, or easiest, way to re-jet a carb.
    I either have to decrease gas flow or increase air flow. I don't think I'm gonna put a RAM AIR unit on it, so I'll have to re-jet to smaller somehow.
    You elude to something like " once you get the jetting sorted out" Well, I'm trying to get the jetting sorted out.
    AL had a link to a vidio that explained what 4-stroking was and it is exactly what my bike is doing. So PLEASE, how do ya fix it? Can ya buy smaller jets?
    Thanks
    Big Red.
     
  11. motorpsycho

    motorpsycho Active Member

    yeah you can buy smaller (or bigger) jets from s.b.p.
    they are dellorto jets, but they will screw into the stock old style n.t. carbs.
    http://www.sickbikeparts.com/catalo...ucts_id=116&osCsid=af32grskqnh6amgp6r77ejhdp3
    the threads have a slighly different pitch so they will screw in hard...but they will screw in and out with out messing up the threads in the carb (they did for me anyway).
    I have a variety of the delorto jets laying here that i probaboy won't ever use.
    I can let you knwo what sizes i have if you are interested in buying them from me.
    I will sell them to you for $2.00 each plus postage if you are interested. s.b.p. sells them for $3.49 each plus shipping
     
  12. Big Red

    Big Red Active Member

    Jets

    Thanks Moto, I,ll take you up on that as soon as I figure out what size I need. I found them at SBP after a google search that put me on to that other site.
    I guess the stock size is 0.70, But I don't know how much smaller to go from there. In your opinion, what is the very smallest I should try? If I go real small I could always enlarge it but I'm afraid I couldn't get it like factory.
    Look through your stuff and see if you have a .60mm, .64mm and a .68mm. I'll buy all three if you do. But first I want to hear back from you about just how small I can try. If you think a .60mm is way too small then I'll take your word for it.
    All this time my motor was 4-stroking and I had no idea what the heck was wrong untill I saw your link. Thanks again for that. :bowdown: I've never had this problem before.
    Big Red.
     
  13. motorpsycho

    motorpsycho Active Member

    ok, i'll look and see exactly what jets i have.
    I'm pretty sure that i have from .60 up to .76 or something.
    I had to use a .72 in one of my carbs, and a .74 in one of my other carbs.
    When i get home from work, i will look and see exactly which jets i have and let you know.

    As far as what jet to start with...that's a ****-shoot. No 2 engines /carbs will work the same with the same jet. Lets say that one engine runs great with a .74 jet in it. An identical engine, with similar mileage, and in the same area of the country may be too rich with a .74 in it, and it may require a .68 to run good. No 2 engines run the same and no 2 carbs work exactly the same. So it's hard for me to advise you on what jet woudl work best for your engine.
    for example, one of my engines was running way lean with the stock .70 jet in it. I ended up having to go up to a .74 jet for it to run right. NORMALLY when you read is that the stock jet is too rich, and you need to lean it out.
    well, mine was the opposite and the .70 jet was too lean.

    Lets guess that your jet is a .70 right now, and it's 4 stroking.
    I would drop down to like a .68 to start with. Whenever you are trying to lean out the air fuel ratio by re-jetting, it's best to change the jets in very small increments.
    you don't want to go from a .70 down to a .60 right off the bat because a SMALL change in the jet size can give huge results.
    you need to figure out the current jet size and then work down in jets sizes in steps until it runs the best.
     
  14. Big Red

    Big Red Active Member

    Jets

    Thanks Bro,
    as far as I know the stock size is .70mm. I don't have any way to confirm that right now. I still would like to try the .68mm, a .66mm and a .64mm.
    PM me and let me know what the postage is on that.
    Thanks,
    Big Red.
     
  15. Big Red

    Big Red Active Member

    Jets

    Hey Moto, I sent a P.M. to you but I want everyone to know what an enormous help you were to me. Got the jets today and can't wait to try them.
    It's just too hot today to work in my shop. Tonight after it cools off I'm screwing in a jet and taking my new baby for a ride. Wish me luck.
    Big Red.
     
  16. motorpsycho

    motorpsycho Active Member

    No problem....I try to help out people when i can.
     
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