Bike dying when choke is off

[paulosportz]

Hey guys,

I got a Lei 125cc and I've been running my bike with the choke on as when the choke is switched off, engine just dies. I've tried turning up the idle but it still stalls when choke is off.

What is the problem and how can i fix it? Does it matter if i run with the choke on? ive noticed when im at full throttle, at full speed sometimes i feel like a jerk or it engine cuts out a little. If this because the choke is on?

im fairly new to this stuff so any help will be much appreicated.

 

[mattyy]

teh problem may be your air filter not recieving enough air, with your loss of power or engine cuts.
rofl thats what u get for a chinese bike.

could of purcahsed an atomik. They're pretty decent for a china bike.

 

[headsmess]

its a fuel issue...strip the carb down if nothings loose, then maybe just clean it and reassemble it....

could be anything from a blocked fuel filter, kinked hose, the clip on the needle fallen off, to a blocked main jet... using the choke means ADDING fuel(or cutting air) either way, making the mix rich...so...clean your carb first

the cut out at full throttle is definitely fuel delivery probs

thats my advice...pay up please

 

[01nutracing]

I agree with Headsmess, it is starving for fuel, not air. some things it may be:

First thing to do before pulling stuff apart is pull the fuel hose off the carby, turn the fuel tap on and make sure fuel flows through the line freely. Its a pain to pull evrything apart and find that it was only a blocked or kinked fuel line.

Blocked carby jets. If its new its common to get bits of tank plastic in the carb. Clean out the carby and fit an inline fuel filter. http://www.miniriders.com.au/mini-tutorials/16270-carby-pull-down-rebuild-tutorial.html

Check the mixture screw on carb. If its a mikuni copy its probably under the carb towards the front. 1 and a half turns out is a good starting place but check how far its out first, if its about 1 and1/2 to 2 tuns out than leave it there.

slight chance it could even be a vacume leak around manifold but if I had to bet on it I'd go with the blocked jets cause its very common with these cheap chinese fuel tanks

 

[mattyy]

yeah something with ur fuel.

LOL

 

[Jaz808]

I think your choke is off, and you have the on / off backwards, if its the carby with the black plastic thumb lever that pivots in 2 places then up is choke on and down is choke off

Does it look like this

 

[paulosportz]

I think your choke is off, and you have the on / off backwards, if its the carby with the black plastic thumb lever that pivots in 2 places then up is choke on and down is choke off

Does it look like this

Jaz your right on this one. The choke has been off the whole time, thinking it was on. I realised when i took apart the carby and noticed the position i thought was off, had the flap closed.

So its fine now, although i havent tried starting it cold with choke on. Hope it works.

 

[headsmess]

choke never does anything with the flap styles anyway...completely utterly useless

but really good at causing mass confusion

unless youre in say, subzero temperatures?

 

[Danity]

Hehe i like it up here in Darwin...so hot that ive never even used my choke b4

 

[paulosportz]

its a fuel issue...strip the carb down if nothings loose, then maybe just clean it and reassemble it....

could be anything from a blocked fuel filter, kinked hose, the clip on the needle fallen off, to a blocked main jet... using the choke means ADDING fuel(or cutting air) either way, making the mix rich...so...clean your carb first

the cut out at full throttle is definitely fuel delivery probs

thats my advice...pay up please

your correct about the fuel issues for cut outs during full throttle

the main jet was blocked. All fine now after the whole carby was cleaned out. I now installed an fuel filter to prevent the jets from getting blocked again

thanks for help

 

[parasupaman]

For a blocked jet, here is one suggestion for clearing a blocked jet, without having to fully strip down and clean out the carb and jets:

1) Remove the air filter completely, exposing a bare intake hole

2) Ensure the bike is in neutral and the engine is running

3) Hold a slight yet constant throttle to the engine, raising the revs a little above idle

4) Then cover the intake hole completely with your hand (or any other appropriate object you can think of that would completely seal up the air intake hole).

With absolutely no air available to be sucked in, the only thing available to be sucked in is fuel. So the sheer amount of fuel being forced in should hopefully clear the blocked jet. Obviously though, at this point the engine will die. However, hopefully the blocked jet should be cleared at this point, without the need to strip down and completely clean out the carb and jets.

I have tried this a couple of times with a friends bike (who's jets always seem to be blocked due to running without a fuel filter - fuel filter is currently on order through the mail) and this has been successful in his case.