Motorcycle Repair: 1978 honda cm 185 wont start, honda cm, 4 ohms

Question
I have a 78 honda cm 185 twinstar.  It was running well when I bought it, though it seemed maybe the carb was a bit dirty.  I recently made the mistake of trying to jump start my honda when I was stuck on the road and my battery died.  I recently replaced the battery and all electrical systems are working, as in it turns on and all lights work/ it will turn.  but there is no spark and it will not start.  I replaced the spark plugs, which were fuel fouled and there still isn't a spark.  I don't know much about electrical systems and how it gets to the spark plugs.  What could I have fried trying to jump it?  and does my carb slightly leaking mean anything?  

Answer
Nick, I guess you found out the hard way that the bike has a 6V battery in it and you probably jumped it with 12V source.

You probably burned out the ignition coil and the rectifier and any light bulbs that were lit at the time.

You can do a basic test on the ignition coil by unplugging the two small wires and checking the continuity with an ohm meter. It should read about 4 to 4.5 ohms across the primary windings. If you do get that reading then you need to check the ignition points next. The contacts faces need to be clean and shiny, then turn the engine over so that the points are as far open as possible. Measure that gap and adjust to about .014" plus/minus .002" Then test the points with a test light attached to the hot lead on the points. The points must just OPEN when the F timing mark are aligned with the mark on the stator. The points are just a mechanical switch, but they need to be clean and adjusted properly. You should get a spark at the plugs with 4 ohms at the coil and the points cleaned and adjusted correctly.

Carb leaking slightly is usually due to a float valve that is worn/dirty. Carb probably needs idle jet cleaned, main jet cleaned and the float valve cleaned or replaced.

http://www.cmsnl.com/honda-cm185t-twinstar-1978-us_model1043/partslist/  for parts references.

Bill Silver