POWER JET how does this work?

[hallsy]

Can someone explain how or when the power jet on my 03 YZ 250 works? In a diagram the manual indicates this jet can have an effect from fully closed to 1/2 throttle, but notes: that it closes at 8,500 rpm. Then states "the richness of air-fuel mixture under 8,500 rpm to the extent of 1/2 to full opened throttle can be set by changeing the power jet". I'm so confused please help.

 

[hallsy]

Nobody? This is my first MX bike, don't most modern 2 stroke MX bikes come with this type of carburetor?

 

[KXtrailrider]

Ok my KX has one. I'll try to explain. It is a fuel circuit that is controled by the ignition system, when there is power to the powerjet it is closed leaning out the jetting for more overrev, when there is no power to the powerjet it is open and fuel flows through the circuit making it richer for a stronger midrange. The ignition uses the RPM and the throttle position sensorto control the opening and closing of the powerjet solenoid. If you unplug the power jet solenoid the bike will be rich at high RPM but should run good everywhere else. Hope this helps. Ed

 

[MX86]

really good invention to help throttle responce

 

[hallsy]

Ok, then is the solenoid simply open from idle to 8,500 rpm? or does the throttle position sensor dictate when the solenoid opens, say like at 1/4 throttle or what?

 

[kawamaha]

http://www.*********************/e/tipse.htm
type supercross-online point de where the ** are. then click on YZ250
why I am not allowed to post my homepage link :whoa:

 

[hallsy]

With that information I'm assuming the power jet adds fuel only when there is a load placed on the motor and below 8,500 rpm?

 

[KXtrailrider]

Pretty much yes but it adds fuel by being turned off, no electrical power to it, then a around 8500 power is sent to it closing the fuel off. The idea is to get a strong midrange with a good overrun.