Topic: bike not starting just clicking when starter pushed

[mackdaddy27]

so, I'm new here and to working on bikes but am relatively mechanically inclined.
I am the proud new owner of a 1975 cb750 that I have begun some small modifications to.
I swapped out my stock turn signals and brake light.
My lucas style brake light had only 2 wires, so I added a ground that is connected into the harness and grounds on the mounting bolt of the light - working perfectly.
My signal lights are actually dual filament but I am only using one wire and I have added grounds to these lights at their mounting points and run to their appropriate harness locations.
My bike was running perfectly prior to this signal work, and even starting and running great once the original lights were all removed (I just cleaned the carbs and replaced plugs and it was starting beautifully.
I went to ride it last night and it won't start.  When the starter button is pressed it just clicks.  The battery has full charge and all instrument lights and button function as they should, including the lights, but it will not start.
I did blow the rear brake light fuse somehow in my work, but swapped that out.
Is it a grounding issue?  maybe a loose ground in the headlight from tinkering around?
Does anyone have an idea of what could be wrong?
Please help.

[ekpent]

  Place a large screwdriver blade between the two large terminals on the top of the solenoid and see if the engine cranks. There will be some sparking so be forewarned but that area is where I would start investigating. .

[evanphi]

  Place a large screwdriver blade between the two large terminals on the top of the solenoid and see if the engine cranks. There will be some sparking so be forewarned but that area is where I would start investigating. .

don't hold it for long or it will weld on!

If the starter spins when you do this, its the solenoid or switch.

If the starter DOESN'T spin when you do this, it's the starter/wiring. Start at the solenoid and follow the wires!

[flybox1]

Battery Voltage bike off?
Battery voltage w key to ON?

[Hondawggie]

Did you try to kick start it?  if it was running fine before and the electric starter is offline, it should start.

Clicking -- sounds like battery.

Each battery cell should be 2.1 volts DC, for a total of 12.6 volts on the battery.
If you get between 12.55 to 12.65 measured on the battery *while the bike is switched off* then the battery measures okay.

You can then do a "load test" -- after verifying you've got around 12.6 volts on the battery with the bike turned off -- now turn the key to 'on' but do not start the bike (say, with the kick starter).   Now measure the battery voltage.   If the battery drops below 10 volts, you may have a weak battery. 


- How old is the battery?  Any white cells in there?


Once you get it started with the kicker, set the RPM to 2500 to 3000 RPM and verify you've got 14 volts DC   across the battery terminal.   If not, maybe your charging circuit has a fault and the battery isn't getting recharged during riding.

[calj737]

Battery Voltage bike off?
Battery voltage w key to ON?

This ^^^^ If you have been testing and tuning your battery to get electrics to work, you've run down the battery more than you realize. "Battery fully charged" is not sufficient. What is the exact voltage with a meter?

[millla03]

I agree the battery is a good place to start. Just went through this myself a couple weeks ago. My (4+ year old) battery had sufficient charge to kick start and run, but didn't have the cranking amps to turn the starter even though it showed sufficient voltage. Symptoms were that of a short or bad ground in testing. Wouldn't trigger the starter solenoid unless the positive starter cable was disconnected. Dropped a new AGM in and it starts better than ever. I would go through the starting system as others have mentioned, and load test the battery. Should be easy enough to find what's at fault with some troubleshooting.

[b52bombardier1]

A voltage measurement alone is only half the equation.  If a battery cannot deliver sufficient amperage then it is dead.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

[SOHC4 Cafe Racer Fan]

The clicking sounds suspiciously like a battery issue.  (from experiencing the same when my li battery fell below a certain voltage never to return)

[strynboen]

turn the light on..and see if it goes dark..vhen the start button are pushed...if the light goes off..it often the battery going low.

.a night at the loader..and try Again..or use start wires from a car

[calj737]

A voltage measurement alone is only half the equation.  If a battery cannot deliver sufficient amperage then it is dead.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

True. But I never list the hour when asked what day of the week it is. Know what I mean. If voltage is LOW, Amps don't matter.

[mackdaddy27]

Thanks ekpent and evanphi. I bridged the solenoid as suggested and got spark. So...I then proceeded
to disconnect and reconnect all wires in headlight in case my sing along installation worked one loose.
But, thanks to calj737 and others I also checked my battery. I thought it had a charge as the lights were working but urns out it had desire from all my testing and checking.
sohc4 veterans 1, rookie bike guy 0
Thanks for all the help. You guys are a great resource.
Off to ride now. Summer is short up in Canada so every night is precious!

[evanphi]

Thanks ekpent and evanphi. I bridged the solenoid as suggested and got spark. So...I then proceeded
to disconnect and reconnect all wires in headlight in case my sing along installation worked one loose.
But, thanks to calj737 and others I also checked my battery. I thought it had a charge as the lights were working but urns out it had desire from all my testing and checking.
sohc4 veterans 1, rookie bike guy 0
Thanks for all the help. You guys are a great resource.
Off to ride now. Summer is short up in Canada so every night is precious!

Especially if you're on the East Coast like me. Keep the rubber side down!