"big twin" 40hp backfires regardless of plug wire orientation

[sgm98ws6]

So i just tuned up the ignition system with points, coils, high tension leads, condensers, and plugs. Now when i go to start the motor it will backfire through the exhaust. It does this either way i put the plug wires. I thought i had them backwards but it does it either way. Would wiring the coils to the wrong set of points give this condition?

 

[HighTrim]

Re: "big twin" 40hp backfires regardless of plug wire orientation

What year is it. My guess off hand, is that it is a motor that requires 105 ft/lbs torque on the flywheel nut, someone guessed at the torque, did not do enough, then sheared the flywheel key. OR used a hardware store key, OR the crank/flywheel were not cleaned with acetone prior to installing. They must be clean, and torqued to spec, and must be OEM parts.

 

[boobie]

Re: "big twin" 40hp backfires regardless of plug wire orientation

Have you got the coil primary wires going to the correct set of points ??

 

[sgm98ws6]

Re: "big twin" 40hp backfires regardless of plug wire orientation

So i may have not set the points correctly. Got my manual back out and pulled it apart and sure enough points were off. Reset them,made sure wires were out of the way. sprayed just a little bit of fuel down the carb and it fired up on second pull.