Motor will not fire

Anyone come across this before? I have a 80cc 2 stroke kit that i installed and ran it about 5 miles then it quit, would not spark.
I replaced the coil the magnito and magnito wheel, the spark plug, added a direct ground, tried starting with and without the kill switch connected, no luck.
Am i missing something?
Any help I would be grateful.
Dave

My problem is spark not fuel.
I went through all wiring even plug wire everything is correct the same as my other builds that i have.
I have done 10 builds in the past 3 months and this 1 motor is a mystery to me.

Was told the magnito magnet could be on backwards, is this true? No markings for in or out? And only fits on one way.

Here's one for the books.
My motor that won't spark;
I removed everything 1 piece at a time and installed on a working motor and started it each time,
that's the coil with plug wire, the plug. magnito and magnito magnet everything works the bike runs.
Now i took the parts that i know were good from the running bike and installed on other motor even flipping and replacing the magnito magnet. No kill switch installed no plug connectors, extra ground installed from motor to bike frame and guess what?? IT DON"T SPARK!!!!
My supplier called me last nite and said will replace it, i just need to pay shipping and was told to keep the one that won't start for parts.
Thanks for all the help and suggestions.
Dave in Naples