Carburator is smoking

[Jake_the_potato]

i had a brand new kit but it would not start so i took it to a mechanic who tuned the hell out of it and fixed all of the backwards parts from the factory, it was running great for a day, now it will start has no power then it backfires and a small cloud of exhaust comes from the air filter then it dies, now it will not start. i called the mechanic and he said lower the needle so its not so rich this did not help, please help me its a new kit only ran for a day

 

[Deleted member 12676]

did the mechanic increase engine compression?
sounds like it's firing too early.
make sure the magneto is in the correct position. take off the left side cover to see.
take out the spark plug to see if the piston hit the ground electrode closing the gap.

 

[Purple Haze]

I agree with Jag, it sounds like the timing. With the piston @ tdc, the keyway on the mag should be at 1 oclock. Also, if your "mechanic" hogged out the ports, that can throw the timing off, as can changing the height of the cylinder with different gasket thickness. My guess would be the magnet being installed wrong.