Dies after starting

[Dougmcd87]

Hi guys after i start my bike about ten secs later it will start to sputter bogg and die so I start to full throttle and it dies and sometimes backfires I then start it back up and it's like crap again but this time after 20 30 secs of warming up it will run perfect and idle perfect, anyone know what could cause this cheers

 

[crassius]

new motors often run poorly when cold - clears up after motor is run in a bit

 

[Dougmcd87]

It's done 300 to 500 hundred miles so far is this normal even thou was working fine past month or so I also had a bad cdi but then replaced it second one was faulty but third time lucky do you think this may be the cause?



Seems more hassle fixing these lil ht engines I spend more my time fixing than riding sometimes lol
"I shall not give up , I shall not give up"
Just kidding and thanks for the help crassius

 

[crassius]

Did you try taking out the mag and filing the surface around the 4 screws that hold it to the case and make the ground connection?