i posted this in the tech area, but not get any replies.

2003 883c 12500 miles since july 1 2006

oil changed (syn) every 3k-4k

my sporty recently decided to start misfiring, back firing, and then stalling.
it only happens with a hot engine, usually after 10-15 minutes of riding.
i ride 56 miles to work @70-90 mph, and the same home, everyday.
i think that the high rpm, heat for the sustained amount of time everyday may have effected the ignition module, or coil, or might be the bank angle sensor.
it happened this morning, and i pulled the plug, and it had no spark, i looked everything over, jiggled all the wires to plugs, coil, battery, and it decided to spark.
it fired back up, but this is happening everyday, and always with a warm/hot engine.
ive been watching closesly all the sppecifics when it happens, and it is usually even throttle, not coinciding with bumps.
the one constant is a hot engine.

the battery wires are secure, ground wire is secure.

 

Been conferring with a buddy of mine, here's a few thoughts...

There's three basic elements that make an engine run, especially an engine as simplistic as an air-cooled motorcycle engine: fuel, spark, and air. I think you should examine each of those areas. Granted your problem is coming about when the engine is fully warmed up, but it probably wouldn't hurt to check all three systems.

Fuel: Fuel could be boiling if the line is too close to the exhaust. The line could be clogged or fouled. What condition is the cable in?

Spark:Are the spark plug cables old/worn? Are the spark plugs themselves fouled at all?

Air: Is your air cleaner in good shape? Filter clean?

Just some thoughts, hope this helps!

 

My 2006 XL1200C ran like this when I fouled the plugs.

 

Insure your battery cables are TIGHT. Do not just jiggle them.

 

Goto radio shack, get a can of that electonics freezing spray.

Pop the plates off over the points.

When this event happens spary those electronic points.

If it starts there's your problem ...

 

It is a 2003....there are no points.

 

You are feezing the electronics ...

 

Sometimes the coil acts up simular to this.

 

Had a ign module drive me nuts once. Found out after 2 modules that the primary case was heating up due to lack of oil.The heat got the lower cases hot enough to crap out the module. Only happened at hwy speeds. let it cool down and it ran great. Don't know if this could apply to a sportster

 

Could be ignition module, could be plugs, change plugs first. I'm betting on the electronics(module)