Motorcycle Repair: 1978 honda hawk 400 t2, regulator rectifier, honda hawk

Question
starter will not engage. Stored 25 yrs. Previous owner purchased new batt. Charged wrong. Minus to positive ETC ouch. I Replaced with another new batt. Now nothing happening. Jumped starter solenoid and the starter works. What did he cook???  

Answer
Randall...

Well, it could be minor or it could be really bad for the electrics.  SEE:

http://www.cmsnl.com/honda-cb400tii-78-us_model7218/partslist/F++17.html  
    #3 the silicone diode-rectifier (not the rectifier for the charging system) that keeps feedback signals from activating the starter circuit when the clutch switch is not activated.

Check all the fuses in the fuse box, of course. If the headlight comes on when the ignition switch is ON, and then goes out when the starter button is pressed, then the switch is probably okay.

I think it just popped the diode.

http://www.oldmanhonda.com/MC/WiringDiagrams/MCwiring.php#class for wiring diagram info.

You can just jumper the diode wires together to bypass the diode function to test it. If it starts, then check the charging system output when it is running. If it isn't charging the battery, then the regulator-rectifier might be dead as well.

Bill Silver