Ive got a 06 harley 1200 sportster when it warms up it starts to cough an sputter through the carb dosent do it all the time but on ocassion it runs fine just takes spells that it does it rebuilt the

SOURCE: 2003 dyna lowrider,sputters spits and coughs.clears up when you p

Check HT leads, connection and the spark at the plug to see if it nice and bright.

Is the battery charged fully or is it old? They don't last very long on Harleys.

See if the regulator is any good ( dealer or friend swap if possible to check).

SOURCE: 2003 sportster wont start or run right when it is warmed up

this may or may not be the same as mine, but I have an 03 XLH 883 and it comes to find out that the Ignition location and componeets is a lot different in most models. Finding parts and information has been a travesty at best. First thing is, everyone uses a different name for the same thing. On my model as it turns out, the Crank/ Cam Positioning Sensor is the same as the Ignition Module. On other Bikes it is mounted elsewhere. From all the reading and searching I have done, each of the symptoms are slightly different, as well as components mounted in different locations. unfortunaly there is alot of confusion on this topic even though it seems like it is fairly common. the new module was quite difficult to locate and replace. PLus the directions/ wiring are quite vague and cloudy. The first Module has 5 wires but the new one only has 2. It is not clear which wire goes to which side of the coil, so be careful when you hook it up...

Gar

• 384 Answers
• Posted on Jun 11, 2009

SOURCE: missfiring, banging on over run,starts after about 10 minutes

Weak or failing ignition coil and/or module will cause this, as will a flooding carb.

SOURCE: when it warms up it miss fires

I had the same problem with my 04 1200C. It was a defective crank position sensor. replaced the sensor and no problems since.
Good Luck

SOURCE: I have a 03 Harley XL Custom Sportster that has a

You are experiencing a lean condition (to much air vs fuel) due to your exhaust and k & n filter modifications. This means you'll have to re-jet you carb so more fuel is introduced so proper ignition can take place. Running lean will result in detonation and big dollar repairs. If you have fuel injection you will have to purchase a fuel/ignition management module i.e. power commander, sreaming eagle race tuner or the like so you can upload the correct air/fuel mixtures as per your mods.