eBay performance carburetors

Discussion in 'Performance Mods' started by Ronen, Jan 6, 2016.

  1. Ronen

    Ronen New Member

    I have the stock NT carburetors and I want to upgrade.
    How are these eBay carburetors? http://www.ebay.com/itm/391331737568

    Even that it's looks like cheaper generic of these one: http://www.jnmotorsbikes.com/product_p/jnm1128.htm
    Are they giving at least near as much more speed and upgrade?
    And are they also semi automaic and doesn't need to andjust like the second one?

    Also I saw on ebay something that looks like cns or minuki:

    Are they can give also some more power and close even little to the original?
    And what is the two throttle cables on top?
    Thanks, Ronen

  2. crassius

    crassius Well-Known Member

    the NT has good mixture control for the flow of a standard motor - if you improve the flow of the motor (porting, trick exhaust, etc), then a performance carb may get you more power
  3. jaguar

    jaguar Well-Known Member

  4. Timbone

    Timbone Active Member

    Those Dellorto clone RT carbs are a big improvement on the NT. The RT uses a slide (as opposed to a needle) and has a semi-automatic choke. It just works better. Employ the correct jet for top end cruise and you are golden.
  5. Ronen

    Ronen New Member

    Do you mean the first one with colored filter or the one that has two throttle cables on the top and choke lever?
    And what is to employ the jet? do you mean to adjust it or to use a jet kit like this: http://www.jnmotorsbikes.com/product_p/jnm1130.htm
    Thanks, Ronen
    Last edited: Jan 6, 2016
  6. Timbone

    Timbone Active Member

    Your first two pics (Ebay and JNMotors) show what appear to me to be RT (stamped Ron Tang???) carbs to me. They require a RT throttle cable that threads onto the throttle slide, a big improvement over the stock NT carb. The upgrade to a RT carb made a world of difference to me.

    I don't have experience with the other type of cab pictured.

    Each carb has a jet, basically, a round fitting with a very precisely drilled hole that allows fuel to be introduced to the cylinder. At high RPM, fuel mixture is dependent on carb jet size. Too big a jet, and the motor will run too rich and bog down when you work towards WOT. Too small a jet, and the bike will run too lean. They are very easy to replace and experiment with.
  7. Ronen

    Ronen New Member

    Ok thank's! I will get one of these
  8. Purple Haze

    Purple Haze Active Member

    Stay away from that last one pictured, it's the CNS, a tuners nightmare.
    Timbone likes this.
  9. danlandberg

    danlandberg Member

    I agree with Purple Haze, the CNS carb that came with the Grubee 66cc was junk (in my opinion). It could NOT be tuned to run as well as the stock NT carb. All adjustments were LocTite'd so you would strip the screw heads. Once loose, no mater what I did made this carb work as well as the NT carb. I also did not like the choke set up (thumb control and we already have toooo many cables). For the simplicity of the NT carb, the "SPEED" carb works great for me. I have just a few HP mods. Expansion Chamber, NGK B7HS plug, billet high compression head. The stock NT carb comes with the kits from 48cc - 66cc. The "SPEED" carb has a larger intake Chanel and slide. Matched with a billet aluminum intake manifold (the are ported) you will feel the difference in performance with the simplicity of the NT design.
  10. Frankfort MB's

    Frankfort MB's Well-Known Member

    What are the best overall carb that you can buy under 50$? I've heard nothing but good things from the walboro (chainsaw carb) due to the ability to change the fuel mixture but they seem difficult to install since you have to drill holes in the jug.... Also thought about the delarto clones but don't you have to buy a different throttle cable? I was just wanting a carb for better top end speed
  11. HeadSmess

    HeadSmess Well-Known Member

    the stock standard NT carb works perfectly fine.

    these are NOT high performance engines that require sensitive throttling. they will not spit you off into the gravel if opened wide from a standstill.

    the majority of users are WOT or idling. why worry about what happens in between? as long as it runs?

    learn to tune the NT first before bothering wasting money on BLING

    if you want a good, easy to tune carb...get a walbro.
    or zama, the cheap chinese walbro. they are both frustrating to fit, needing special adaptors, air cleaners, and usually, cable mounts... money, money and more money. sold by someone with lots of words and no real proof. you pay, they make money. yay.

    no carb is going to ADD top end power or speed. learn to port first. learn to weld and make tuned exhausts.

    until you can tell if the needle taper is too steep, or the slide cutaway is too large... just keep the NT.
  12. Frankfort MB's

    Frankfort MB's Well-Known Member

    I've done all of the above excluding the custom exhaust and I was going to buy one next and build one off of that... Me and my buddy's have drag races lol so I wanted a carb that would help all around power but also the motor can take only so much fuel....
  13. 45u

    45u Active Member

    This is the next carb I am trying and it has a low speed adjustment. Not cheap but when you buy the best it is not cheap. I have a SHA clone it is OK but no low speed adjustment.
  14. 45u

    45u Active Member

  15. Wolfshoes

    Wolfshoes Member

    My 2012 Grubee 66 engine was fitted with a Ron Tang made Dellorto Clone stock 12 mm from ebay. It cost $23.99 and included the cable and free freight from XJY Ming in Chino, CA. Running poorly on a new carb sold for this engine, the jet was about a 62 number size drill. Buying a set of Forney micro drills from ebay, the jet was soldered shut and starting with a number 76, the ritual was begun of running the bike and checking the color of the the spark plug and moving larger one drill size at a time. At drill size 70 the plug was looking wet and the uphill performance was weakening. Drill size number 71 appears to be optimal. Out of curiosity, I opened up the stock CNS carb and measured the jet. It was a loose 71 drill size, almost a 70. No big surprise the jetting of these carbs probably are in a close range to each other. Changing the carb did not by itself improve the uphill, upwind performance of the engine. The EPA CNS carb does not appear to have unique jetting that would hold back performance.

    The choke would not disengage by itself at full throttle on the RT carb, and having no manual way to disengage, it had to be removed. The carb arrives with no instructions. A Bikeberry online video as well as the Jaguar website is helpful. There did not appear to be any need to drill another hole inside the carb for low speed performance being stock 12mm and used at about 600 ft in elevation. The filter element was similar to the screen used over a kitchen oven.

    In conclusion, I would not be a hurry to move away from the stock carb on a stock engine. In the future, I would consider a adjustable carb that does not require manual jetting even if it costs more.
  16. danlandberg

    danlandberg Member

    The "Performance" CNS carb that came with one of my GRUBI 66cc engines, was, in my opinion, "JUNK". Could not get the adjustment screws to turn (probably loc-tite). After finally getting them to adjust (practically ruining the screw heads) the carb still would not work for crap. The stock NT carb worked better. I found the NT " SPEED" Carb worked better yet. I think the simpler the better.