NT carb idle trick

Discussion in 'Intake & Exhaust' started by Kartooo, Jan 12, 2017.

  1. Kartooo

    Kartooo Member

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    did 2 builds with china girl and NT carbs. been a mechanic for over 40yrs and love the simplicty of these things. no problem with needle/jet/float stuff all coming out OK except for idle on #3 build. too lean. has a 4 position needle. position 3 from top too rich all around. position 2 OK all around but too lean at idle. broken in, no vac leaks, #65 jet, 40 oil mix, b6hs, head bolts at 12ft lbs with copper head gasket.

    raised the float just a bit above the std 21mm and nice idle now !! dance1

    i have found subtle changes in all these kits/carbs. some needles are longer/shorter, 4 groove/5 groove. clamp has a tab to hold the square nut/no tab, different slide return spring. length of clutch arm short/long. nice casting/bad castings, fine thread/course head studs. they all run different and require different carb settings.
     
    #1 Kartooo, Jan 12, 2017
    Last edited: Jan 12, 2017
  2. crassius

    crassius Well-Known Member

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    yeah, I've been telling folks here for many years that float level can move you 1/2 a notch on clip
     
  3. Kartooo

    Kartooo Member

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    good info crassius
    these little engines sure are sensitive to carb adjustments
     
  4. crassius

    crassius Well-Known Member

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    few folks look at most of the info here - everyone wants one-click answers and then demands that they be latest, trending, info

    would take a lot of work to organize all info here into a nice reference, but everything needed has been here for quite a while
     
  5. Kartooo

    Kartooo Member

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    these kits are not plug and play. without some mechanical skill and access to a data base of knowledge like found here one could get pretty crossed up.

    in the early 70's i ran the parts dept at a honda dealership. i was always playing with jets/needles/timing/sprockets on my CB160. my owner's manual stated a top speed of 84MPH. when all tucked in i could slowly pass a friend wide open on his 305...
     
  6. ZipTie

    ZipTie Member

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    yes Kartooo I agree, no two are alike... just like fingerprints. Its like they use what components are laying around. Also Its all copies of copies of copies of a copy with engines and components, I suspect is the problem. Think of it as engine lotto. But they are still a blast to tinker and drive. I love the simplicity, and cheapness of spare parts, its refreshing.
     
  7. Kartooo

    Kartooo Member

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    DSCF1418.JPG hey ZipTie did you get your rear rack tank from Dax ? got mine mounted on my 37 columbia, no fenders, no chain guard or chain guard mount, frt drum brake, 40 tooth manic mechanic, that nice engine mounted tensioner you sold me on. engine sits nice and looow without the chainguard or mount.
     
  8. ZipTie

    ZipTie Member

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    No I didn't order it yet as I wanted to see yours first. I love it. I need to get now for sure and put on my Columbia. I'm going to bob my rear fender and just have the small rear one on and toss the front fender in the junk bin. Your bike is looking stunning with the all black engine too. Yes, I see you went with the quality tensioner, in looks and function, best tensioner out there, bar none. Good job. You should start a new thread on your Columbia build and post more picts!
     
  9. ZipTie

    ZipTie Member

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    Kartooo, I just ordered the rack gas tank. 58.00 bucks with shipping. should be here in 7 days.
     
  10. Kartooo

    Kartooo Member

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    GREAT ! it's not plug and play... it is set up with the filler cap and petcock to the rear. toooo far to run the fuel line. i got the ol dremel and cut off wheel out to reverse it. you also have to take the bends out of the 2 struts that go to the seat clamp so the tank is level.
    DSCF1419.JPG
     
  11. Kartooo

    Kartooo Member

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    another great source for parts is Lynn https://mbrebel.com/ she has a kazillion wheels. it's where i bought my frt wheel/drum brake. very reasonable.
     

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