help on minibike please

[ed675]

Hi! i have a 212cc predator mini bike with a mikuni carb and its very hard to start. when i get it started it just wants to take off. Can you guys plz help. thank you

 

[buckeye]

Welcome to OldMiniBikes.
Could be several things.
Throttle adjustment.
Clutch
Chain
Idle adjustment

 

[ole4]

Can you provide some more information? What is your starting procedure and what mikuni is on it? Is it trying to take off with the throttle enrichment open? If you shut the enrichment lever does it slow down? Is it hard to start with the enrichment on or off? It should be on to start a cold engine.

 

[DeadPixel]

Dose it go full throttle on you after starting?

 

[red baron]

Without more info it's hard to help. Sounds like a lean condition. a manifold air leak or air screw adjustment.

 

[cheezy1]

Where are you located in Mi? I can look at it if you are in the Detroit area.

 

[ed675]

Without more info it's hard to help. Sounds like a lean condition. a manifold air leak or air screw adjustment.

Can you provide some more information? What is your starting procedure and what mikuni is on it? Is it trying to take off with the throttle enrichment open? If you shut the enrichment lever does it slow down? Is it hard to start with the enrichment on or off? It should be on to start a cold engine.

It wont start when choke is on. I think it has 22mm mikuni carb on it. Then when choke is off it wants to take off. Then if you put choke on it turns off.

 

[Havasu Dave]

On those, the enrichment lever (there is no choke) can be confusing as to "off and on." Is there any chance you have it reversed in your mind? (I have been there) Plunger Down, Lever UP, Choke is Off.

Once started, it is taking off because your RPM is high enough to engage the clutch. It is impossible to troubleshoot accurately over the internet, but you are going to have to educate yourself on your particular carburetor, and it might not be a Mikuni, but a Mikuni clone, which is still a good carburetor.

I found this web page to be a good starting point for educating myself. It was enough to confidently adjust and fine tune my carburetor.

 

[ed675]

Alr thanks. It says mikuni on it. Also its super hard to start. It takes around like 20 pulls to start it and it still dies down after 10 secs

 

[DeadPixel]

Is it taking off due to high RPM or is the clutch engaging to soon? If it is RPM you might have a small vacuum leak.