cut's out at haft trottle

[44oEX]

my friend has a 300ex and he blew the motor, so he change it and know it runs like *****. it cut's out at haft trottle. I told him to take it to my house and I would check it. I figured the jetting so I played with that a little but ends up that the jetting is stop on.

So my Q it what else could it be???
could it be the CDI or something like that???

[2004TRX450R]

On the left side of the engine down low there should be a black steel cover. Remove it and there should be two wires under it. One is for the neutral light and the other is for the reverse light. Unplug the reverse light wire and see if it helps.

[44oEX]

OK i'll let the guy know but in what way could that help ( what would it do )

any other ideas

[44oEX]

thanks I told the guy and it works great know.