help with the nt carb

rock out

rock out

New Member
So I upgraded from the CNS carb to the nt one now I find that when I'm riding if I hit a bump the little choke arm bounces up killing my engines power is there a way to tighten it right now I just put a rubber band to hold it down
 
rock out said:
So I upgraded from the CNS carb to the nt one now I find that when I'm riding if I hit a bump the little choke arm bounces up killing my engines power is there a way to tighten it right now I just put a rubber band to hold it down
Click to expand...

Remove the nut, spray the thread off with some carb cleaner or something to remove the oil that is on it, put a dab of blue or red loctite thread locker on the threads and screw the nut back on tight enough that the lever needs a medium to fair amount of resistance to be moved up or down, now leave the bike to sit for a couple hours so the loctitie has a chance to harden.

This is one way to do it, personally I just ping the threads where the nut and threads meet, I take a sharp pointed center punch, I place the point of the punch where the threads and nut meet and give it a couple good taps with a small hammer, this will ping a dent in the thread on the outside edge of the nut and nut allow the nut to vibrate loose once the tension of the nut is where I want it, thos is a simple and no cost way to fix the problem you're having.

If you decide to se the pinged thread method just remember not to go crazy and hammer to hard or you could break the carb.

Hope this helps ya out.

Map reddd
 
Cool thanks a lot. Also another thing is I only have a top speed of 40km/h when I pedal hard
I got the gt2b 48cc Grubee motor with performance expansion chamber and nt carb 44t sprocket I think I'm expecting too much out of this engine does that top speed sound about right to you?
 
rock out said:
Cool thanks a lot. Also another thing is I only have a top speed of 40km/h when I pedal hard
I got the gt2b 48cc Grubee motor with performance expansion chamber and nt carb 44t sprocket I think I'm expecting too much out of this engine does that top speed sound about right to you?
Click to expand...

Im familiar with how fast 40 km/h is bit I have always got and easy 28-30mph with a 41-44T sprocket, the carb will need to be jetted smaller I and the exhaust may need a little modifying for better flow to get above where you are now, but if the engine is fairly low miles that can play a part in top speed not being at full potential yet, some of these engines need more break in time than others and the fact that you have a 48cc rather than the 66cc engine I always use could be some of it also, but I think most people normally realiz at least 30mph from a well tuned 48cc engine.

Map reddd
 
rock out said:
40kmh is only roughly 24 mph
Click to expand...

Well im gonna say your speed is a little slower than it should be for a top speed, 24-25 mph should be a good cruise speed even with a 44t sprocket oj a 26" wheel.

Maybe a bit of jetting change on the carb, is the engine 4stroking while you're at top speed?

Map reddd
 
Does it Gurgle and not really "Top Out" No Seriously-- I too must re-jet smaller with all motors I run.
 
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Yeah it kinda sounds odd when I'm reaching its limit.
I swapped to not because I didn't like the CNS specially the choke cable and for some reason it was bogging down the engine
 
rock out,

I lifted these form a post from Barelyawake from over three years ago, hope you dont mind B.A.

this is another thing you should do to the NT carb to help the lower to mid mixer, on all of my engines while running the NT carb I have needed to raise the clip on the needle to the second from the top notch, the pix here will show what you will be seeing when you remove the carb slide, hold screw on part/top where cable is and then push the slide so that the spring is compressed and you cable remove slide form cable so that you can adjust the clip position, use needle nose pliers to snap clip on and off of the needle if that clip flies away theres a good chance you wount find it, so dont do the work in the grass or dirt get on a good surface so if the clip does fall you have the best chance of finding it.

here are the pix
IMG_1108.jpg


IMG_1121.jpg


IMG_1109.jpg


IMG_1119.jpg


notice in last pic where clip is on needle, this is where most of us run it and it seems to work out best in that position.

This isn't the final fix for a carb that is running to rich, you will still need to jet the carb down to get the best tune and for the engine to run at its best, this is only an adjustment that will help along with the smaller main jet you need in the carb.

hope this help.

Map reddd
 
Also....

There is a small guide pin down in the throat of the carb where the slide goes, be sure when reassembling the carb that you line up the slot that is in the slide with the pin in the carb or you will mess up the slide and jam it up in the carb.

Again this is a pic from BarelyAwake that I lifted from the same thread as the other ones.

If someone wants to go over the entire thread about this subject here is the link

http://motorbicycling.com/showthread.php?t=20956

IMG_1127.jpg



Map .wee.
 
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I really like the nt for simplicity and not crowding up my handle bars also worked like a charm right out of the box I'll still keep the CNS in case the nt breaks down
 
So I switched the needle clip up the the second from top I didn't really notice much difference but I didn't really ride much. I think there might be a small hole between the flanges I'm not sure if it penetrates through to the inside of the motor I'll have to disassemble it someday
 
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