I have a slightly odd problem with my 2002 FS.

When I go to start the bike, the starter cranks well but the bike doesn't start while it's cranking. However, as soon as I release the starter button, the bike immediately starts and runs perfectly.

The starter motor DOES stop as soon as I release the button, but in the fraction of a second after releasing the button, the bike starts.

My suspicion was that I have a battery problem and the voltage is dropping too much while cranking so that the spark is weak. My theory was that as soon as I release the starter button, the voltage to the coils increases and that's why the bike starts.

However, I've checked my battery and I have 12.7v with ignition off and 11v while cranking. I would have thought this was OK.

Does anyone have any ideas? Are those voltage readings too low? Or do you have any other theories?

 

put some jump leads from your bike to your car and see what happens then - that will tell you if it's a battery problem or not.

 

Excellent idea - thank you. Embarrassed not to have thought of that!

Sadly it didn't solve it though.

 

Did jump-starting auto battery also drop voltage to 11v when cranking?

If so, either auto battery is bad or you have bad jumper-cable connection.

Try putting battery on smart-charger for 24-hrs. Want at least 13.5v fresh off charger.

For example, here's my VFR after 4-months winter storage without being on tender (lithium battery).



I turn key to ON for 10s for pump to prime carbs. Then push start-button. After 3-revolutions >VRRROOOM<. Voltage-drop when cranking says lots about condition of battery.

 

I didn't check the voltages when jump starting. Absolutely should have done!

I'm leaving the battery off charge overnight so it settles to its natural voltage. I'll then re-do the voltage checks tomorrow and also do the same while the bike is connected to a car.

I lifted the tank earlier and sprayed all injector and coil connectors with contact cleaner. I also checked all the vacuum hoses. Didn't help!

I've had another suggestion of a possible earthing issue so I'm going to have a check of that in the morning as well.

I'll report back!

 

Video attached in case it helps (assuming my upload works ...)

 

Have you checked the starter relay?

 

I haven't as yet, no. I assumed that it's working OK to get the starter to power up and down as per the video.

Did you have a specific type of failure in mind - very happy to check it if it's a possibility. I'll try anything that the symptoms suggest is a problem!

 

The relay is designed to shut off everything not involved with starting, then power everything back up when not cranking. Perhaps the ignition stuff isn't being powered while the relay is in cranking position. I'd give that a look as well as the wiring from that terminal

 

Thank you - I'll take a look.