Mini Dirt Bike accelerating automatically

[Mave]

Hi.

I just got a Mini Dirt Bike (49cc) and it's awesome.

But 2 days ago I was riding through some grassland and I fell (not hard but I fell)
Now everytime I start the bike it auto accelerates and then shuts down.
I can prevent it from shutting down by lifting the back wheel, if I then start it it does auto accelerate but doesn't shut down, then I have to get on it while holding the back wheel still in the air, put the back wheel down and I can drive it.

Any suggestions?
I really love the bike but I hate this problem.. :/
I'm thinking some problem with the cable that leads to the accelerator handle.

Also please explain like you're explaining to a noob, because I am a noob bike-wise.

I don't have a picture, but it's almost exactly like this one:

 

[GooseMan]

so can you control the throttle at all, most likely your cable is getting caught on something.

 

[my67xr]

with the throttle on the hadlebars,
look underneath it, you'll see a rubber boot on the end of the cable.
pull it back away from the throttle, and down the cable a little.
is the cable sitting into the seat properly?
maybe pull the cable a little and check it pulls itself back into the throttle again.
if it does then refit the boot.

the other thing to look for is a kink in the cable somewhere, or that the cable is not seated at the carby end.
check the carby end of the cable, the same way i advised with the throttle end.

post up your findings

 

[rotn50]

Sounds like the centrifugal clutch has broken a spring or 2, as when you start it the bike stalls out cause the clutch is engaging with load, and when you lift the wheel off the ground it doesnt stall because there is no load on the wheel and it is free spinning, its a bit off track from the throttle cable but is worth a look in mate, good luck

 

[8r3nd0]

Does the bike seem to rev faster then when you first got it if so then yeah your throttle cable is the problem or your revs are to high, if the carb is like the one i had on my little 2 stroke road bike then there is a screw with a spring attached to it on the carb turn that out. When these bikes rev to high the centrifugal clutch engages and it starts to take off.

 

[rotn50]

Now everytime I start the bike it auto accelerates and then shuts down.
I can prevent it from shutting down by lifting the back wheel, if I then start it it does auto accelerate but doesn't shut down, then I have to get on it while holding the back wheel still in the air, put the back wheel down and I can drive it.

relooking at it i think you guys are on the money with the cable, can be hard to try and determine something from someone elses description, these carbys that they run also have an adjustor in the top of them, maybe it jumped out due to being loose or at the end of its thread.

 

[zwebx]

if the cable is all good look for air leaks...