Atomik Nitrous 140 starting problems

[my67xr]

or, that there is dirt/plastic bits or bits of rubber fuel hose getting stuck in your Needle and Seat
bits of hose can break off when you are removing refittiing you fuel lines when playing with the carby.

 

[Flynn629]

Ok so what should i do first?

 

[zwebx]

Ok so what should i do first?

carby off, bend the float tab so it sits level (with closed needle and seat) then pull the pin out of the float and look on the needle and seat for debris or any reason it would not seal if fine the re-assemble not bending the tab again

 

[Flynn629]

Hey man not quite understanding what your trying to say, could you try put it real basic and simple way for a complete kook please thanks heaps mate appreciate it

 

[my67xr]

so start by taking the fuel line off the carby,
then take the carby off the bike

grab your camera when you start taking it apart,
and get pictures of it before you pull it apart for reference when reassembling



tip it upside down over a clean icecream container or the like.

the barb on the top of the carby, where the fuel hose slips onto, will leak some fuel out
look into the container and see if there are any tiny bits of dirt/debris in the bottom of the fuel
if so, any one of these could have stopped the needle and set from sealing shut.
this will make the carby overflow out the vent holes



now remove the fuel bowl screws, and take the bowl off.
dry the rubber gasket straight away, otherwise it will expand.


the 2 black plastic parts joined by a brass bracket need to come off next
there is a pin that goes through the brass bracket, look at the end of the little towers.
you should be able to push it out with your finger, or a biro/pen tip if you need.
it will come out the opposite end.
now the float is just balancing there, gently lift it up and off the carby.
it might take the needle with it, the little part that sits on the centre tab of the bracket.
now sometimes the needles have a thin loop of wire that hooks over the centre tab of the bracket.
when you reassemble the carby, make sure it hooks over the tab.

slip the needle off the tab, or remove it from sitting in the seat on the carby base
you will notice it has a rubber pointed tip, look closely at it for any dirt/debris, or nicks in the rubber.
it it looks ok, give it a wipe and put it to one side.
now look at the bottom of the carby, there is the big round brass tube, where the needle sits into
this is called the seat.
in the centre of the seat there is a hole, that's where the fuel comes through from the carby
if you can see any dirt/debris in there, then try and blow it through, out the barb on the top side
some carby cleaner could help dislodge anything that is stuck there.

once you are all happy it is clean,
then you can refit the needles' wire loop over the tab on the centre of the float.
then sit the float back down in position, making sure the needle slides nicely into the seat.

now slide the long pin in that holds the float into the 2 little towers
so it is now back together, minus the fuel bowl


turn the carby the right way up again, and slip the fuel hose back on,and turn the fuel tap on.
fuel will run out the base of the carby, at the needle and seat.
gently lift the float. and when it is sitting roughly level with the base of the carby,
the fuel should stop flowing out
if the float needs to be lifted more than level, the centre tab on the float bracket may need rebending
let us know it that is the problem

but, if it is continuing to leak out, then there could be more debris stopping it from sealing.
so, i would go back a few steps and repeat the cleaning/checking method i described above.

once it is not leaking when the float is lifted up to level with the base
then i would say you are all good to refit the fuel bowl.

do up the 2 screws, refit the carby to the bike, and try it out.

let us know if you have problems still.

 

[my67xr]

if there was any dirt in the needle and seat,
i would remove the fuel tank from the bike, take the fuel tap off the bottom of the tank, and give it all a good clean out with petrol/degreaser and check it is clean before refitting it.

then i would be fitting a fuel filter to the hose between the fuel tap and the carby, just cut the hose somewhere in the middle, and slip it over each end of the filter
they can be bought quite cheap form auto parts stores or lawnmower shops, about $2
this should help the problem to not reoccur

 

[my67xr]

this is a different carby but will give you an idea



sliding the float retaining pin out




the needle and seat, inbetween the towers



the needle




the seat




this pic shows roughly at what height the fuel should shut off at, when you lift the float
see the centre tab of the float bracket to the left,
it should shut off the fuel when that pin is pushed into the needle, but without the floats touching the top up inside the carby

 

[Flynn629]

Yea cheers bro got her fixed up and took her for a decent ride no leaking which is great. But for some reason my bike gearing feels shorter now like it revs high without the speed being there and feels like all the gears are shorter. Mayby im just going nutz who know haha can something cause this or is it just me? Cheers

 

[my67xr]

so what was the problem, was it just dirt in the needle and seat ?



have you tuned the carby mixture screw yet ? like i explained before




you might get a bit more top end by adjusting the needle clip too?
the clip is on the top of the needle that hangs out the bottom of the carby slide, there are 5 notches that can adjust the mixtures for the top end revs
they are usually set in the middle position (3rd notch down) standard
the top slot is the leanest, then works it's way to richest at the bottom notch


to get to it,
unscrew the top of the carby and slide the lot out.
then you need to compress the spring up into the cap, pulling it up and out of the slide.
now try and push the cable downwards into the slide, and at the bottom you will see the end of the cable come out.
grab this and you should be able to slide the cable out through the long slot of the slide
next, there a clip holding the top of the needle into the slide, unhook it and put it to one side
then you can take the needle out the top of the slide.

it will look like this

if you slip the clip off (don't loose it)
and move it down 1 notch towards the point, it will richen the mixture a touch

so once you have changed it to the next notch don, refit the needle into the slide, then refit the retainer clip
now compress the slide return spring back up into the cap of the carby
and hold the cable out as far as you can
slide the cable back into the long slot in the slide,
and hook the end of the cable back into the cutout in the bottom of the slide
pull the cable in though the slot at the top of the slide
then let the tension off the slide return spring
the sldie and carby top can now be refitted and take it out for a test ride

try it and see if there is any improvement

 

[Flynn629]

Its already got a smaller sprocket for better top end. Like yesterday i had tuned it in perfect for good smooth power and stuff. But it was just after the leaking problem it has gone weird.

 

[my67xr]

did you check the float height/level like i said ?

does it have a smaller rear sprocket ?


if stuff went though your needle and seat,
it may have caused a blockage in your Main Jet, the one in the centre of your carby underneath ?
the jet inbetween the pilot jet, and the needle and seat in the picture below

did you check all of that when you had it apart cleaning ?

 

[wrightyboy111]

Hey mate. Atomik's a great brand and yes, it should kick back. It's because the 140's have a high compression rating. And like the others are saying, it would most likely be a valve clearance. It comes very tight when you get it out of china. It happend with my bike, as soon as i did the clearances, it runned as smooth as butter. I hoped i helped you bro!
@wrightyboy111

 

[zwebx]

Hey mate. Atomik's a great brand and yes, it should kick back. It's because the 140's have a high compression rating. And like the others are saying, it would most likely be a valve clearance. It comes very tight when you get it out of china. It happend with my bike, as soon as i did the clearances, it runned as smooth as butter. I hoped i helped you bro!
@wrightyboy111

00RACING now have a cdi that retards the ignition and 99% reduces the chance of kickback

 

[my67xr]

Hey mate. Atomik's a great brand and yes, it should kick back. It's because the 140's have a high compression rating. And like the others are saying, it would most likely be a valve clearance. It comes very tight when you get it out of china. It happend with my bike, as soon as i did the clearances, it runned as smooth as butter. I hoped i helped you bro!
@wrightyboy111

9/1 isn't that high compression

 

[Flynn629]

Hi again guys, just got a flat yesterday and took my front wheel off. For the spacers one is longer then the other which side does the longer one go in as i didnt notice when taking the wheel off. Thanks alot

 

[zwebx]

Hi again guys, just got a flat yesterday and took my front wheel off. For the spacers one is longer then the other which side does the longer one go in as i didnt notice when taking the wheel off. Thanks alot

Just find one that seems to make the most sense on the brake disk side, so it is centered on the caliper okay

 

[my67xr]

the longer normally goes on the brake side.
but, double check the wheel is central before you do it all up

 

[Flynn629]

Hi again guys, i went to go for a ride this morning and the fuel is gushing out the overflow tube at. The bottom it wasnt leaking when i finished my last ride it just did it when i was going to go ride today. I took carby off and blew air into it and cleaned jets and did the test were u turn the fuel tap on then make the float level and the fuel stopped coming out. But when i put carby back on it kept leaking fuel and it was coming out a small hole where the air filter goes. Please help guys cheers thanks

 

[my67xr]

sounds like the float level is a bit high ?

the flat side of the float needs to sit pretty well level with the base of the carby
otherwise you will need to bend the little centre tab of the float arm so the float closes earlier.

 

[my67xr]

could also be a bit of dirt, grit, plastic etc stuck in the needle and seat.