Motorcycle Repair: CB350 wont start, starter motor problems, starter solenoid

Question
Bill,
You information is great and I've been following your advise. but ... it still wont start. A quick overview.  I rode mostly RD350/400s in the 70s and 80s. I decided to start a project bike. I picked up a 72 CB350 In great shape but have had some trouble getting it to fire. It started last fall but would barely run. So I Clean the carbs, very  well, new points and condensor and battery and now the starter wont turn it just clicks, and she wont start. A have 12 V to the points and spark at the plugs. Any suggestions would be greatly appreciated. Thanks,
   Doug in PA

Answer
Doug, if you have a fully-charged, correct battery with 12.5+ volts, then the starter solenoid contacts are corroded over. In some cases, you can disassemble them enough to clean the contacts and reassemble. Otherwise, you will have to chase down a good used one. As a test, jump a screwdriver shaft across the solenoid contact posts for a second. That puts 12volts and all the available battery current into the starter motor. If that doesn't turn it over, then you have starter motor problems. If the starter spins over, but doesn't engage the crankshaft, then you have starter clutch problems (usually the 3 springs need replacing). You will need a special tool to pull the rotor off the end of the crankshaft, however. Remove the center rotor bolt and screw in the special tool, which is available at many motorcycle shops.

If you have the timing right and the carbs cleaned properly, you should be able to kick start it, with a full choke. Some of the early Honda carbs had little spring loaded doors on the choke flappers. Because of the high velocity of the intake pulses, the springs often failed, so the doors were undermining the choke function, by not staying closed during cranking.

Make sure that the fuel tank is clean, the petock passages are all clean and clear, so you have full fuel flow to the carbs. The gas cap has a small vent hole just outside the gasket, which needs to be open to allow fuel flow to the carbs.

If the ignition timing is not set properly, at the F and LF marks, then check the spark advancer unit for sticking and/or for a point cam that is 180 degrees out. Point gap should be about .014" at maximum lift and then move the point plates until they open at F and LF marks.

Bill Silver