1974 1000 sporty, front cyl doesn't fire

SOURCE: misfiring 2000 sporty 1200

Try replacing your plugs with Autolite's. make sure to get the right size for your bike. See if that makes a difference.

SOURCE: Rear cylinder not firing

The first thing I would do is replace the spark plugs again. You can foul a plug and it will cause you more problems than you can ever imagine. I see you have done all the logical things that I would recommend but I did not see you have replaced the plugs after the 200 miles. You would be surprised at how many times a $2.00 part can cause fits beyond belief.

SOURCE: Backfire when I get off the throttle and down shifting

no your totally wrong the backfire is bcause if u juice the throttle there is excess fule in the cylinders witch give it no where to go so it ignights and creates a backfire witch is not necessarly bad.

SOURCE: I have a 1990 fxr with a single fire ignition, cam

With a single fire ignition, you cannot swap the wires. A dual fire ignition, yes, but not a single fire. You need two things to get the cylinders to fire, spark and compression. Take the plugs out of both cylinders. Run a compression test on the rear cylinder. You need at least 100 PSI to get the cylinder to fire like it should.

Next, put your plugs in the wires, (they should already be in the wiresand grounded) and spin the engine over. Watch for the plugs to spark,especially the rear plug. If you have spark and compression it should run on the rear cylinder. If it still doesn't run, either something is way wrong with the ignition or a very bad air leak on the intake.

If you don't have spark at the rear plug, you need to check the coil. A single fire coil is different from a dual fire coil. The primary wiring is different as well. If you've got the primary wired incorrectly, you won't get spark at the rear plug. Go to the website of the manufacturer of your ignition system. Most of them have downloadable installation instructions. Check your primary wiring.

SOURCE: Not getting spark. Changed coil - still no spark.

Disconnect the small wires on either side of the spark plug wire tower. Then, turn the switch on and check the wires for voltage. If you don't have any voltage, check the "Run/Stop" switch. The voltage for the "Run/Stop" switch comes straight from the "ignition" circuit breaker under the seat. The voltage to the circuit breaker comes directly from the ignition switch. The voltage for the ignition switch comes directly from the battery.

If you have voltage to the coil but still no spark, it sounds like your timer/pickup is bad on your engine. It is located under the small round plate on the right side of your engine camchest cover.