1996 115hp evinrude not starting and backfires.

[klashoot]

I have a 1996 115hp evinrude. It stopped running going up the lake and pulled it home and found out I had no spark on any of the plugs. Change the CDI unit, plug wires, optic sensor and coil packs. I checked it and now have spark on all spark plugs. But it will turn over and backfire and not start. It had been sitting a while before I installed the new parts. What could it be? Any help would be greatly appreciated.
Thanks Kenneth Anderson

 

[Edchris177]

Are you sure the plug wires on on the correct places? Sounds like a plug is firing out of sequence.

 

[klashoot]

Yes pretty sure they are correct. Now thinking the carburetors need cleaning. They set a pretty long time with the old gas in them. Thinking some cylinders are getting fuel and others are not. Does this make sense and would cause the no start and backfire? And thanks for the reply.

 

[racerone]

Remove carburetor drain plugs.----If end of that plug has " green varnish " on it you might be right.----Remove high speed jets and check them for varnish.-----Carburetor bowls might be warped as well.------Stop running the motor until you correct this.----Starving the motor of fuel risks major damage.