ktm 250 exc tpi

I put my brother's pre mixed petrol straight in to the tank of my 300 tpi as he mixed up the fuel cans. ever since it starts up and cuts straight out. Any ideas please on what I could do to solve the problem please guys?

Hi, All! Resently I bought KTM EXC 250 TPI. But after assembling I got "check engine" lamp. youtube.com/watch?v=opVo8gumhBQ I have checked all connections to all electric elements. But problem is not gone. I bought a "gray" bike without any support. As I understand EXC have only CAN(Hi,Low)...