Dear Pw's
I am facing problem in using my Margalla on petrol, its on CNG whenever i switch it to the petrol and drive it for sometime the engine switches off especially when i took my foot off from the accelerator, and when i try to start it again sometimes it start immediately and sometimes it took a little time and i could also see black smoke(especially after long self). The carburetor and butterfly work were done two months ago. i don't know what could be the problem and what is the solution.