carb help!

[jimmmmmy]

hey guys, is it possible to push start the bike if the carb overflow?

thanks in advance for your help!

[NSRog]

i think should turn off the fuel tap. kick a few times. turn on ignition and kick til it starts. den turn on fuel tap.

[jimmmmmy]

i already tried but to no avail. or is bcs of something else?

[NSRog]

maybe. best is to get it tow to ur mech.

[d0n]

pushstart only works if yr bike is electric start + battery is flat.

 

for carb overflow, ideally u should drain out the excess petrol frm the carb.

[KeraKing]

pushstart only works if yr bike is electric start + battery is flat.

 

bro this is not true.

 

yes, you can push start if its overflow.. just keep on push starting.. hehe

you might want to check the sparks too though..

if no spark also no use pushing.

[epk]

carb overflow most probably spark plug also wet already. when you kick start, DON'T open the throttle. if after a few kicks it can't start, turn off your ignition and kick a few times. then turn it back on and kick again, it should start.

[Rahza]

off petrol and engine.. kick slowly just to let the air flow in.. switch the engine to on and try.. else push start.. if still cant take out the plug and dry it den try.. else use new plug.. if all else fails.. it just means ur screwed.. tow ur bike to the shop.. lol...

[ProFatSir]

off petrol and engine.. kick slowly just to let the air flow in.. switch the engine to on and try.. else push start.. if still cant take out the plug and dry it den try.. else use new plug.. if all else fails.. it just means ur screwed.. tow ur bike to the shop.. lol...

 

this is the correct way.

[vfrT]

carb overflow most probably spark plug also wet already. when you kick start, DON'T open the throttle. if after a few kicks it can't start, turn off your ignition and kick a few times. then turn it back on and kick again, it should start.

 

 

Afraid this is not the right. If the cylinder is overflow with fuel, it means there is too much petrol in it already. The only way is to "flush" out them out. One way is stop the fuel supply to the cylinder temporarily, turn on the ignition,open the throttle full wide open then kick start until it starts to sputter.

What this does is the ignition and max air intake(on the open throttle) will dry/burn out the excess fuel in the cylinder. After maybe a dozen kicks, it should restart.

Note I said stop fuel supply to the cylinder - closing the fuel **** will not stop fuel supply until the carb bowl has drained dry. So quite a bit of kicking will be required.

 

alternatively, remove the spark plug and let the fuel evaporate thru the plug hole for say, 30 mins. While you are waiting, clean out the plug. The replace and kick start with fuel throttle open as described above.

[Raptor]

If carb overflows.. it only means that the float needle is unable to sit when the float is lifted up by the fuel in the carb bowl. This can be caused by dirt or sediments preventing the fuel from being allowed to flow into the bowl even though its already full... hence the overflow.

 

Sometimes, knocking on the carb bowl can shake the sediment off and stop the overflowing.

 

If the carb is overflowing.. it means fuel has flowed into the engine combustion chamber too. Now the fuel air ration is too rich and trying to start the bike at this time would only wet the plug and it won't start also because of the over rich mixture.

 

If the bike is laid down as in a crash or fall... the same thing will happen, the carb will flood the engine too.

 

The correct way to start a flooded engine aka over rich engine is to slowly turn the throttle to full max open. Without closing the throttle.. crank the bike over with the starter or kick start. The electric starter nor your leg can kick the engine over at the operating speed.. so this will allow alot more air into the combustion chamber to dry it out fast. It will take a longer than normal cranking to start the bike but it will enventually start... provided you don't close the throttle.

 

What the engine need now is air not fuel.

 

It is a misconception to think that opening the throttle max will lead to more fuel going in... it won't. Unless your electric starter or kicking can spin the engine at max rpm where the low pressure drop in the carb can draw fuel up the main jet. It is impossible to do that with the starter or kick starter.

 

The other option is to remove the spark plug and crank the engine over a few times to 'pump' out the excess fuel from the combustion chamber.

 

Keihin FCR race carbs are more prone to flooding. They have an accelerator pump which squirts a jet fuel into the inlet of the cylinder when twisted fast. This squirt is to compensate for lack of fuel during sudden wide throttle operations so there is no 'bog' or lag during sudden acceleration. So people who keep twisting the throttle to start a Keihin carb bike do not know what the crap they are doing.

[omnislash]

If carb overflows.. it only means that the float needle is unable to sit when the float is lifted up by the fuel in the carb bowl. This can be caused by dirt or sediments preventing the fuel from being allowed to flow into the bowl even though its already full... hence the overflow.

 

Sometimes, knocking on the carb bowl can shake the sediment off and stop the overflowing.

 

If the carb is overflowing.. it means fuel has flowed into the engine combustion chamber too. Now the fuel air ration is too rich and trying to start the bike at this time would only wet the plug and it won't start also because of the over rich mixture.

 

If the bike is laid down as in a crash or fall... the same thing will happen, the carb will flood the engine too.

 

The correct way to start a flooded engine aka over rich engine is to slowly turn the throttle to full max open. Without closing the throttle.. crank the bike over with the starter or kick start. The electric starter nor your leg can kick the engine over at the operating speed.. so this will allow alot more air into the combustion chamber to dry it out fast. It will take a longer than normal cranking to start the bike but it will enventually start... provided you don't close the throttle.

 

What the engine need now is air not fuel.

 

It is a misconception to think that opening the throttle max will lead to more fuel going in... it won't. Unless your electric starter or kicking can spin the engine at max rpm where the low pressure drop in the carb can draw fuel up the main jet. It is impossible to do that with the starter or kick starter.

 

The other option is to remove the spark plug and crank the engine over a few times to 'pump' out the excess fuel from the combustion chamber.

 

Keihin FCR race carbs are more prone to flooding. They have an accelerator pump which squirts a jet fuel into the inlet of the cylinder when twisted fast. This squirt is to compensate for lack of fuel during sudden wide throttle operations so there is no 'bog' or lag during sudden acceleration. So people who keep twisting the throttle to start a Keihin carb bike do not know what the crap they are doing.

 

A really nice read.

[slowrider]

If carb overflows.. it only means that the float needle is unable to sit when the float is lifted up by the fuel in the carb bowl. This can be caused by dirt or sediments preventing the fuel from being allowed to flow into the bowl even though its already full... hence the overflow.

 

Sometimes, knocking on the carb bowl can shake the sediment off and stop the overflowing.

 

If the carb is overflowing.. it means fuel has flowed into the engine combustion chamber too. Now the fuel air ration is too rich and trying to start the bike at this time would only wet the plug and it won't start also because of the over rich mixture.

 

If the bike is laid down as in a crash or fall... the same thing will happen, the carb will flood the engine too.

 

The correct way to start a flooded engine aka over rich engine is to slowly turn the throttle to full max open. Without closing the throttle.. crank the bike over with the starter or kick start. The electric starter nor your leg can kick the engine over at the operating speed.. so this will allow alot more air into the combustion chamber to dry it out fast. It will take a longer than normal cranking to start the bike but it will enventually start... provided you don't close the throttle.

 

What the engine need now is air not fuel.

 

It is a misconception to think that opening the throttle max will lead to more fuel going in... it won't. Unless your electric starter or kicking can spin the engine at max rpm where the low pressure drop in the carb can draw fuel up the main jet. It is impossible to do that with the starter or kick starter.

 

The other option is to remove the spark plug and crank the engine over a few times to 'pump' out the excess fuel from the combustion chamber.

 

Keihin FCR race carbs are more prone to flooding. They have an accelerator pump which squirts a jet fuel into the inlet of the cylinder when twisted fast. This squirt is to compensate for lack of fuel during sudden wide throttle operations so there is no 'bog' or lag during sudden acceleration. So people who keep twisting the throttle to start a Keihin carb bike do not know what the crap they are doing.

 

You posted so much but the TS didn't even say what type of bike he is riding to ahve a carb overflow.

 

Your thining pattern is ALL about racing this, racing that and straightaway goes to explain the flaws of certain racing carbs.

 

Ppl who want help like the TS , should help themselves by first telling others here WHAT FCUK TYPE OF BIKE HE/SHE IS RIDING?

 

If it is a small displacement 2T bike ( which I kinda suspect these newbies are anyway) then it's as simple as closing the fuel coxk and releasing the bleed screw at the bottom of the carb, to lower the fuel flow by allowing some fuel to escape.

 

Then try starting the bike the normal way.

 

As long as the fuel level fall below the brass vent tube for overflow then the fuel would not keep escaping via the needle valve , which is faulty and have to be replaced.

[shaunty]

hi i'm riding a NSR SP, i cant start the engine cos of suspected carb overflow (petrol on the floor)

 

i tried pulling the choke and starting but doesnt work either. when it does start, it idles for about 5seconds before dying. besides changing the spark plug, are there any other methods to solve this problem? and how do i dry the spark plug if i wanna do it myself?

 

any help is appreciated. thanks in advance!

[crazydj]

pushstart only works if yr bike is electric start + battery is flat.

for carb overflow, ideally u should drain out the excess petrol frm the carb.

 

How come i can push start my YBR?

 

I changed to some horrible shell mineral EO, use shell 95 and never use bike for weeks. I think got water in my tank. Kick start also bike will die. I have to push start and slowly ride off.

 

When engine is warm, its about 1.7k-1.8k rpm. Is it really water in my tank?

[ben1112]

If everything fails, TS can try my method. First, remove the spark plug. Then put the plug back into the plug cap. Then ground the plug, meaning use the shiny part where hex tool is used to open the plug in the first place; to touch a metal surface, eg. cylinderhead. Then with ignition on and kick the kick starter, u can use your hand cos it will be easy to push it down without the sparkplug in place.

 

Note: Do not electricute yourself use a cloth to hold if possible and point the sparkplug away from any fuel source.

 

Okay so what this step is doing is check ur plug got spark or not. Make sure u get a nice blue spark so it means ur plug is not wet or fouled or anything.

 

Next. Remove the plug from the cap and leave it aside. Use a rag and a finger behind it, put your cloth wrapped finger on the hole of the sparkplug and start kickstarter a few times. If any excess fuel it will end up on the cloth. Reassemble everything then start as per normal.

 

 

 

You should be able to a) start your bike. b) isolate the problem, either is spark or fuel or air problem.

 

I use this method to start pesky 2 strokes like ktm2. Should work most of the time.

[ben1112]

How come i can push start my YBR?

 

I changed to some horrible shell mineral EO, use shell 95 and never use bike for weeks. I think got water in my tank. Kick start also bike will die. I have to push start and slowly ride off.

 

When engine is warm, its about 1.7k-1.8k rpm. Is it really water in my tank?

 

Judge for yourself whether your gas tank is prone to leaking rainwater in. If not, it could be the following reason;

 

Fuel in Carb turn bad. Fuel can turn bad exposed to air, varnish and gum forms.

 

Solution, Turn off ur fuel supply, locate a screw at the bottom of your carb. It has an outlet beside it, turn this screw anticlockwise and let all the petrol out onto a rag. Empty the carb of petrol. Then turn on ur fuel c0ck for like one second, when u see fresh fuel coming out, quickly turn it off then tighten carb bowl screw and open c0ck again. Now you should have fresh fuel from your tank instead of that sitting in the carb exposed to air.

 

If you really have water in your tank then replace all the fuel in your tank and repeat steps above.

 

(Extra information, petrol in smaller quantities exposed to air turn bad faster)

[danielsin2]

Where do u stay?

[ben1112]

dan u so enthu to help him until u wanna go his hse ah?

[danielsin2]

dan u so enthu to help him until u wanna go his hse ah?

 

I just realised the Timeline from the time TS posted till now.

 

Im very sure by now his bike should be up and running.

 

[crazydj]

Judge for yourself whether your gas tank is prone to leaking rainwater in. If not, it could be the following reason;

 

Fuel in Carb turn bad. Fuel can turn bad exposed to air, varnish and gum forms.

 

Solution, Turn off ur fuel supply, locate a screw at the bottom of your carb. It has an outlet beside it, turn this screw anticlockwise and let all the petrol out onto a rag. Empty the carb of petrol. Then turn on ur fuel c0ck for like one second, when u see fresh fuel coming out, quickly turn it off then tighten carb bowl screw and open c0ck again. Now you should have fresh fuel from your tank instead of that sitting in the carb exposed to air.

 

If you really have water in your tank then replace all the fuel in your tank and repeat steps above.

 

(Extra information, petrol in smaller quantities exposed to air turn bad faster)

 

Where can i find this screw which you speak of? What is it called? I can only find the idling screw to adjust the idle rpm.

 

EDIT: I found the screw. The drain hose was burried deep and hidden. And its a scaray thought. Anyone with a screwdriver can siphon fuel from our bikes sia. Just turn the scrw and the fuel flows out. And guys, don't drain petrol into a styrofoam cum. It dissolves it. I know, i tried.

 

You guys know anything that can hold fuel which is commonly found in the house?

Edited January 23, 2010 by crazydj

[mepkoh]

if the bike did not fall/ lie on its side and u think it is a flooded carb?/ send it to the shop to get it fix...

if you can remove the carb botttom bowl check the float..( i have no idea how a sp carb looks like)...to confirm that the float is stuck or not if the float is okay..fix carb, clean and dry the spark plugand restart by opening throttle to the max and crank..kick start vigourously..it should start..hope this helps..do not use the choke..