How To Guide NT Carb Tuning Basics

Tumbledove

New Member
Joined
Apr 17, 2011
Messages
15
Thanks for your very clear instructions Irish John. I still could not get the cable to budge at all tho. I may try again at a later time when I am not frustrated with the thing. It runs great without it right now, so I may just leave it alone before I "fix it" real good. :)
 


goodtime65

Member
Joined
Dec 7, 2008
Messages
71
Thanks for your very clear instructions Irish John. I still could not get the cable to budge at all tho. I may try again at a later time when I am not frustrated with the thing. It runs great without it right now, so I may just leave it alone before I "fix it" real good. :)
If you are having trouble releasing the throttle cable than it may help out to remove it from the throtle handle and this will give you more cable to play with
 

jeffuehrer

Member
Joined
Apr 12, 2010
Messages
119
The Float Needle Jet Valve

Thanks for all the pictures and descriptions of the carburetor.

I have recently been having problems with my motor and discovered that the float needle jet valve had unthreaded and was swimming free nilly in the bowl causing havoc. I over tightened it though causing it to break off with a small chunk left in the threading. I had another spare carb and took the float needle jet valve out and proceeded to thread right behind the chunk lodged in there. the bowl is up tight against the main jet now but it is the one with a flathead notch so i'm hoping that fuel will still be able to flow up through the main jet. If it doesn't work what would you guys suggest I do? Thank you in advance.

"If it ain't broke, fix it 'til it is."
 

jeffuehrer

Member
Joined
Apr 12, 2010
Messages
119
Well, It ran great for about 3 miles and I was like "yea, I fixed it!" no you didn't. The spare float needle jet valve dislodged due to the lack of sufficient threading due to the blockage from the previous float needle jet valve chunk. Using my will and ingenuity I devised a plan to unthread the chunk using a mere steak knife. I successfully dislodged the blockage and was thusly able to thread the entire length of the spare float needle jet valve...snug. Lesson 358 learned. Thanks guys, you are all geniuses!

"If it ain't broke, fix it 'til it is."
 

happycheapskate

Active Member
Joined
Nov 5, 2009
Messages
1,389
If the throttle cable is "stuck" or the carb slide will not move freely, it may be installed backwards. I did that once, and the bike started and took off full throttle till I killed it with switch. There is a groove on one side for a locator pin, to keep it from turning, and a notch on the other side where it contacts the idle screw.

I got o-rings from Sick Bike Parts for the carb-to-manifold fitting and the little knurled cap where the cable goes in.
 

jeffuehrer

Member
Joined
Apr 12, 2010
Messages
119
Yeah, the slide notches were my first lesson a year ago. I haven't installed the slide backwards since then. I always have problems with the jet needle valve coming unthreaded. A guy I sold some unneeded parts to today suggested I use blue loc-tite but since snugging it up last night it's been running great. If it falls out again I'll know what to do. I don't have a kill switch. If I need to kill it I choke it or stop and hold the brake then release the clutch slowly. I know it is dangerous not having the kill switch but really the whole motor on a bicycle thing is dangerous if you think about it. Ladies first, safety second.

"If it ain't broke, fix it 'til it is."
 

Tumbledove

New Member
Joined
Apr 17, 2011
Messages
15
If you are having trouble releasing the throttle cable than it may help out to remove it from the throtle handle and this will give you more cable to play with
This may be my next move if and when I need to take the slide out again. I adjusted the c-clip position lower and she bogged. Then I went a notch higher, (the highest), and she bogged. So I just put the c-clip back where it was. I was looking for a little more top speed and to see what effect it may have in throttle response. All of this was done without any finesse whatsoever, pushing the needle and clip through the spring. The c-washer still abides quite content on my desk.

As a side note, does anyone know why the idle screw does not seem to have any noticeable affect on the engine's rpm? I appreciate any and all replies. A safe 4th goes out to all!
 

lewsidius

Member
Joined
Jun 10, 2011
Messages
42
hello everyone
my engine starts but the bike doesnt take off
i move the throttle open and no change in sound
and i slowly come to a hault and the engine turns off
the engine has a good sound and a consistent rythum
i tried the bike before work after tightening the Throttle

the bike idles then as i lose speed the engine gets quiter and i slowly come to a hault

i took apart the carb and the slide is moving proper back and forth
and the spark plug definatly has a strong spark (ouch)
thanks
chris

so i dont know what to adjust or whats wrong????
 
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