back fire & grinding HELP

[CajunBlaster]

tried to start it , there is smoke coming out but it back fires & then kills

 

[blasterboy91]

sounds like its time for a rebulid.my uncles did the same thing.he had ta rebulid his.now idk bout ur details but thats jus wat comes ta mind

 

[hawkeye]

its either time for a rebuild or ur timings jacked up