LCT=Liquid Combustion Technology. Says it is U.S. owned and operated business. I would think parts availability is somewhat limited.
You state weak spark in heading, and say fuel is coming out of the muffler. You have replaced ignition coil and carburetor and apparently no improvement?
Did you have good strong spark with original ignition coil? What type of carburetor is original (brand)? Try pinching off fuel line and starting/running engine.