Motorcycle Repair: CM450E Honda running light/left turn bulb, left turn signal, filament bulb

Question
I've had this 1983 used bike for just over a year now, putting about 5000 on it commuting 40 miles each way when dry and warm. I've noticed the left turn signal light works, but when not blinking (signaling a turn) the running light at first flickered on and off, and now, doesn't illuminate when running straight. Still blinks for turning.  The screw holding the amber lens cap on is rusted and doesn't look to come out easily. What should I do? Replace the bulb? What one do I need for this model? Also, if you replace one bulb, is it common practice to  do the other at the same time (thinking one worn out indicates the other could go). Thanks for any pointers or tips on removing.

Answer
Kirk, the front running lights have a dual filament bulb... usually a common 1157 bulb available at auto parts stores and elsewhere.

The running lights stay on all the time, unless the high beams are selected. The separate turn signal filament flashes when the signals on that side are selected.

Spray some penetrating oil like Kroil, PB Blaster, WD-40 or Seafoam in the recess around the screw. Make sure you use a screwdriver with a nice sharp end and insert it into the screw head. If you have a small hammer, use it to tap on the handle of the screwdriver gently a couple of times, then try to turn the screwdriver first slightly to tighten then reverse to loosen the screw. If it is really bad in there, the screw head will either strip or the head may break off. You have to get the lens off to replace the bulb, either way. If the screw strips the head, then you can use a small drill bit to drill the head off of the screw. If it breaks off, once you remove the lens, you can put a pair of vise-grips on the screw shank and hopefully remove it. These are small 3 or 4mm screws, specific for this application, so replacements will have to come from the dealer or a salvage yard if one is nearby.

Check the bulb socket for a nice clean contact and ground base. The signal must be grounded, usually through the green wires, so ensure that all wire connectors are in good shape.

If you have to, you can use a bit of silicone RTV sealer around the edge of the lens and maybe put some electrical tape around the parting edges of the signal body until you can get some screws, if necessary.

Hope this is helpful...

Bill Silver