[shadetree]

Hi HH
Check out the ignition diagnostic section if you haven't already. I don't know much about the 300s. No spark eh? Sounds like you need to perform a few more continuity and resistance checks.
Stator exciter coil check? Fuel cutoff relay?
https://drive.google.com/drive/mobi...QUNIbV9EN0E?usp=drive_web&sort=13&direction=a

the trx300's don't have a fuel cut-off relay bro, only the old school trx350's have these .

 

[shadetree]

is the kill switch clean and working good ?. ignition switch good and working ?.