Motorcycle Repair: 86 Yamaha FJ 1200, no crank, yamaha fj 1200, model bikes

Question
I have a 1986 FJ 1200 that ran fine until a few months ago, when it wouldn't even crank. Battery is charged up, and I replaced the starter relay as symptoms seem to indiacte this was the cause. Still, no crank. I do notice that when I hit the start button, it acts like it's grounded out. If the head light comes on when keying on, it will turn off immediately when the start button is pushed. There is also a slight rumbling noise when sometimes when the key is turned on. Bike has about 67k on it and up until this point has not had any real issues. Thanks for any insight.

Answer
Bob, I am not a Yamaha FJ expert, but most all later model bikes have a headlight cutout function when you hit the starter button, to conserve voltage for the starter motor.

This is a common problem with 1970s-80s Hondas, as the switches just disintegrated with time and current running through the contacts.

The "rumbling noise" may be your starter motor trying to engage due to shorted out contacts in the handlebar switch.

Bill Silver