Problem with the choke

[yfzgirl]

My son has a 2001 Yamaha PW-50 Yzinger & every time we start it up it runs fine but when we close the choke it shuts off.Does any one know whats causing this to happen?:confused:

[Demon Rider]

Is you carb set too lean?

[yfzgirl]

At first it wasn't even running.So I set the idle,cleaned the air filter and did an oil change on it and now it started to run but every time we put the choke down it, it just shuts off.Another thing, how will I know if the carb is set to lean? Keep in mind, I don't have much experience with 2-stroke's.I also scraped the deposits off of the end of the head pipe.Thinking maybe that might the problem but it wasn't :mad: I would really appreciate it if you could help me out:( .

[Demon Rider]

When you choke your engine you cause the mixture going into your carb to be rich (you increase the gas portion of your fuel to air ratio that goes into the cylinder). In the very extreem for example if you are 100% lean then you only got air going into your cylinder and your engine obviously won't run. Similarly if you are just a little to lean your engine still won't turn over. Thus this setting is very important. If you don't know how to set it bring it to your dealer and they will be able to set it to the exact ratio. In the mean time if you want to set it yourself just adjust the screw slowly and listen to the engine. You should be able to hear when the engine is running right.

[yfzgirl]

I made friends with the mech at my local dealership and he's coming over to check it out on weds.I know exactly what your talking about but I'd rather have him check it out since he's a qualified mech.And for the record your right, cause that's what he said the carb might be running to lean.Thanks again I really appreciate you helping me out with this.