The problem: In 1975, DOT ruled that all street bikes must have Always ON headlights.
The function inside the switch was a hot 6/12volt wire from the ignition switch that toggled between the headlight ON function and the electric starter function.
Sadly, the first-generation starter switches were made with a plastic switch case, which failed, probably due to the heat created by the full-time voltage passing through the tiny contacts.
Normally, previous starter solenoids were fed voltage from the ignition switch circuit that used the grounding of the primary windings through the starter switch to complete the energizing of the solenoid. With the 1975-on edict, the solenoid had to ground the primary side of the windings first, then applied the voltage back through the starter button switch.
Early:
BAT-IGN SW-Starter solenoid primary windings and grounded at the starter button contact, grounded to the handlebars
Late: BAT-IN SW-Starter solenoid primary winding which was grounded at the solenoid mount and then voltage was sent through the harness to the central starter switch contact which completed the circuit with voltage fed to the starter switch contact.
The starter solenoid has a 4-wire connection. The large terminals connect the starter and the battery together when the magnetic solenoid plunger is activated by the completion of the primary wires to B+ and ground. The primary windings don’t care which ones are connected to power and ground. On the CB200T solenoid, the short green wire is grounded by a bolt near the solenoid mount.
On pre-1975 bikes, the yellow/red wire normally goes to the handlebar switch and the lead is grounded to the handlebars when the starter button is pushed inwards.
On later models, the handlebar wire is energized through the voltage in the central starter switch contact when the button is pushed inwards. The solenoid primary is grounded through a green extension lead, which has an eyelet on the end. The green wire is then bolted to the chassis.
Currently, the worldwide supply of model-specific CB200T/CL200T starter switches is down to the extent that any that are listed on the internet have asking prices of $250-300+
OEM CB200T starter switch 35150-389-671
Solution:
I figured that a late CB175K3 handlebar switch would do the same functions, but without the KILL switch function. The CB175 switch needs to be modified by drilling the threads out where the cable adjuster would normally sit with a 5/16” drill bit. You have to be careful not to drill all the threads out, but leave about ¼ of the threads intact to function as a stop for the non-adjustable disk brake cable end.
To access the wiring harnesses I removed the handlebar clamps and rolled the handlebars backwards onto a thick towel placed on top of the fuel tank. This gives access to the wiring harness leads.
I used a thin piece of wire to wrap around the ends of the old switch as it was withdrawn from the handlebar tubing holes. The wire was then attached to the new switch harness and pulled back through the handlebar holes and out towards the hole at the back side of the headlight shell. The throttle cable as attached and the throttle wire connected to the throttle drum. The CB175 switch has the same locating pin inside the housing to index with the locating hole in the handlebar. The two halves are joined with the two screws to lock the switch in place.
The brake cable is installed next into the switch housing and the brake switch and lever installed. The handlebars are rolled back up to where the index punch marks are even with the split in the handlebar mounts and everything is tightened back down again.
With the switch harness ends tucked back into the headlight shell, the wiring connectors must be color matched to the harness leads. The stock left hand switch had the Hi-Lo functions which are no longer needed. The excess wire ends can be cut off or tucked into the wiring bundle. The Yellow/Red wire from the handlebar switch connects to the matching Yellow/Red wire connector from the main harness. Now the wire is going to ground inside the starter switch, instead of going to B+ voltage. The solenoid green primary wire is removed from the ground bolt and attached to the positive side of the battery.
The handlebar switch leads have to connect back to the harness with the yellow and yellow/white wires connected to the harness connectors. The black/white junction has a male pigtail end that connects to the black power junction. The white, blue and green ground leads from the switch connect to the headight bulb connections. The high beam has two blue wire connections to make the high beam function and to illuminate the high beam indicator light located in the top of the headlight shell. Be sure to connect the front brake light switch leads into the matching connectors inside the headlight shell.
It never hurts to keep a few spare fuses handy, in case some incorrect wiring connections are made. I lucked out and when the key was turned on I had a nice bright green neutral light and functioning front brake light switch. Turning the new handlebar light switch ON to Lo and Hi gave me lights in both positions. Tapping the starter button with the bike in neutral gave a quick click and then the starter engaged as normal.
So, the only cost was the OEM CB175 handlebar switch and an hour or two to install it and make all the wire connections match up. I saved at least $200-250 from avoiding the “proper” CB200T starter switch which had a current retail price of $205, although they are NLA from the usual vintage bike parts sources. If you are faced with a defective starter switch, this is one option that can work for you.
Bill Silver aka MrHonda.
www.vintagehonda.com
