Wont run without Choke?

[dhoskins92]

Hey all!
I just put a brand new Lifan 125cc engine in my bike and the new engine also came with a new carb and it runs GREAT! But... It only would run fully choked. After I messed with the fuel/air mixture on the carb I got it to run 1/2 Choke but why wont it run with NO choke?

 

[timeeh]

What way are you turning the choke off? Up or down?

 

[gottagetacheaperhobby]

have you checked for air leaks around your manifold and carby? spray some wd 40 around all the joins while your bike is idling and if there is any change in running speed then you have a airleak and may need a extra gasket

 

[dhoskins92]

I tried the WD40 trick and I think up? Runs so much better now that i messed with the fuel/air screw but still not top notch

 

[Shearer]

Have you check'd jets? as Sounds like they could be blocked in carby!. as choke richens the mixture make run normal. take choke off get no fuel at all at idle with jets blockd

 

[dhoskins92]

Would the jets be messed up even tho the carb has maybe an hour on it?

 

[Shearer]

yeah could be!, be 1st thing i check!. bit of dirt in fuel or plastic fragments dosen't take much to block them up

As when trying to jet carby. pulling the choke on is quick n easy way to test them. As if runs better with choke on means jetted to lean (or jets block'd do same thing). As choke is design'd to richen the mixture for cold starting!.

 

[noypi160cc]

can you re check the choke again. remove the air filter then operate the choke . look at the butterfly plate you will see which way the open/close position of the choke lever.

 

[my67xr]

can you re check the choke again. remove the air filter then operate the choke . look at the butterfly plate you will see which way the open/close position of the choke lever.

Lifan 125 will most likely have the china Mikuni copy 22/26mm carby, which just has a brass plunger on the manifold side of the carby.
with the brass plunger pushed all the way into the carby, (lever down) the choke is off

is this the same as your carby ?

the choke is off in the pic below

 

[my67xr]

maybe try turning the mixture screw out another half a turn, see what difference that makes.

they are a bit awkward to work on, try using a small flat headed screwdriver bit, like the one on the left