QuestionWe're restoring a 1977 360XS that sat 8 years. It has a new battery, and it won't start. It has kickstart, no motor. There seems to be compression, but we get nothing, no sound at all. (Yes, it has gas, and we cleaned out the tank and drained carburator.) The lights work, but no other electrical elements (horn, turn signal and brake lights) do. Manual suggests a short or the ignition is at fault.
Where do we start? If it's a short, what do we do? Could it be the fuse box? We have a multimeter, but its instructions don't discuss motorcyle troubleshooting. How can we test ignition? Any help would be appreciated.
AnswerNancy,
Let's move backwards as they say. Test the plug for spark by removing it, placing it back into the wire cap and hold the threads to ground and kick over the engine. You should see a stong blue spark. If so, go to the paragraph below. If not, replace the plug with a known working one, gapped correctly, and check again. Make sure the coil wire is in good condition including the plug cap. Make sure the coil has the correct low and high tension resistance (procedure is in you manual, you will need your multimeter set on resistance/ohm). Check the condition of the wires from the stator to the coil. Check the condition of the points and the settings, the procedure is in the manual. They should not appear burnt at the contacts. (replace points if needed with a NEW CAPACITER, you will need a generic magneto puller to do this from your local bike shop). Last of all check the kill and ignition switch to make sure they are making proper contact (you'll need to look at the wiring diagram to determine which wires current needs to jump across at diff. key positions). Other than that, the stator/magneto output could be to blame but this is the last thing to check. It requires an ossiliscope to make an accurate assesment (best done by a shop).
If the bike sat for 8 years without emptying the carb or treating the fuel it is possible the carb was left with a film of varnish over all it's interior parts. If the varnish sticks the needle valve shut, no fuel can enter. If it is stuck open, the float bowl can overfill. Normally the excess fuel is diverted out a tube but if that is blocked the incoming air will draw the fuel into the cylinder. Be aware this can foul the plug causing poor ignition.
My suggestion, dissassemble the carb and clean. Here are some detailed basic instructions I've given others on this procedure:
Disassemble, clean all jets and orifaces with solvent and COMPRESSED AIR ONLY, use NO wire or picks to clean holes/airways. Rebuild carbs with new gaskets and make sure your floats are set correctly. Do not overlook the float level (specs. in manual), be very sure you are not starving for fuel. In relation make sure fuel flow is unobstructed and use a good in-line fuel filter from the tank to the carb. Even tiny particles in the fuel can get logged in critical areas and cause havoc.
Hope this helps, take your time and read the manual carefully. If you have any specific questions about anything you don't understand, write back.
Michael
