I just bought a 96 1200 custom bike only has 3900 miles on the clock so it's still damn near new but when I'm riding around doesnt matter If it's hot or cold when I come to a stop light and idle as soon as I try to crack the throttle it coughs at the carb and will even die at times. What could this be?? Running to lean maybe??

Also got stuck in typical rush hour traffic the other day and after about 15 min of 5mph driving started getting some spark knock out of the front cylinder. Again to lean??

 

Conrats on the purchase of a great bike. I'm guessing you need to rebuild the carbureter. Do a search on this site for how to info ... losts of posts regarding this subject.

 

A 96 with only 3900 miles on it needs more than just the carb rebuilt. You need to take a look/test all the rubber intake seals. Take off the petcock and check the fuel filter and rinse the tank out. Check the rubber fuel and vacuum lines. Has the battery been load tested? I'd also test the stator and charging system. I could go on and on.

I doubt that the jetting is the problem.

 

Need more info! Is you bike stock? Do you have any engine mods? If your bike is stock, make sure you burn premium fuel. and change your plugs make sure there burning light brown. if you have any mods ie: intake or exhaust, you may need rejet. I change pipes on my 04 1200 caugh went away. I didnt need to rejet. runs awsome now! Hope this helps, if not there are alot of motor heads on this sight that can help you.

qweeksdraw

 

Like others said if its been sitting a lot at only 3900 miles it needs a carb rebuild. If its had mods to it exhaust/air cleaner then you should be looking at a rejet and carb rebuild. Other thing to check is to see if anyone has messed with the a/f mix on the bottom of the carb. But one way or another your mix isnt right