yfz 450 won't start help needed
 

My 06 yfz 450 will not start. It began when my son rode for a short time and it just stopped. It turns over but will not start....occasional backfire when attempting to start.

Here is what I've already done.

Has fresh gas and valve petcock is on
clean filter
has spark
cleaned carb A to Z
fuel screw set correctly
timing is correct
valves are in spec for both intake and exhaust
all electrical connections are good
tried a known working CDI from another yfz owner and no change to problem
I do have one relay in front that seems damaged...the two that appear identical....are these required to run the motor?

thank you in advance for your assistance!

Welcome to the forums.

You may want to ask this over in the Yamaha section to get more answers.

Welcome