Motorcycle Repair: Honda Shadow 2002, air intakes, pulse generators

Question
Im on my last leg and not sure what to do with this bike. I had a 2002 honda shadow brought in for some work. It started with some problems that led me to believe that i needed to replace the ICM/ECM. the new part helped correct the problem but did not fix it. I have checked coils and wires and the front cylinder is not firing correctly. have checked the air intakes and the cams as well. Front cylinder has a good spark but is not hot!!! PLEASE any ideas would help.
Thanks
JENN

Answer
Jennifer.... I'm not sure which flavor 2002 Shadow you have.... 600, 750, 1100..? You didn't mention what the mileage is on it and previous repair details, so I have to wing it here.

If you have spark and it is strong and steady at the front cylinder, but the cylinder isn't firing, then the remaining causes/issues are:

No/low Compression... pull a spark plug and get a compression tester to measure the actual cylinder pressure. Normally, the figure will be about 175 psi. Check both cylinders and see if they are the same.

If compression values are low, then try adjusting the valves, if you have a model that has adjustable valves. If they are not adjustable, then you may have worn rings/piston issues.

If you have compression and spark then you must not have fuel metered correctly. If you have a twin-carb model, then you could have fuel delivery issues to the carb, clogged fuel flow to the float valve and/or plugged jets on idle/main circuits.

IF the bike will run warm on the choke, but not off of it, then the pilot/idle jet circuit is plugged up. This makes the engine hard to start and it won't idle properly.

Remember that there are pulse generators by the flywheel. Some engine types have a single one and others have two. Check them for proper resistance values.

Note that extensive troubleshooting can cause the spark plugs to load up and fuel/oil foul while you are trying to get it running. Pull the plugs and make sure they are clean and not all carboned up with fuel/oil deposits which can short-circuit the spark process to both plugs. If they are black and oily, replace the spark plugs. Check spark plug wire cap/connectors for about 5k ohms resistance readings.

For specific known issues, try http://www.hondashadow.net/forum/

Bill Silver