The International CBX Owners Association

Just took my carbs off for another cleaning but now I have everything back together the engine will not start. I have electrical power but when I press the start button there is nothing, not even a click. All I notice is the headlight turning off each time I press the button. I tried charging the battery but no change. I must have done something tilting the engine but cannot think what.
I can bump start the bike and it runs fine but nothing when I press the starter button. What am I missing?
Ross

Since it runs when you bump start it, I doubt the main fuse is bad, but would not hurt to check.

I would be concerned about the battery first. Have you charged it, and had a load test performed on it? NAPA, Advance, Auto Zone all have the capabilty to test it. Once you know the battery is good, fully charged showing 13+volts, then test.

You may just have a loose connection at the battery hookup, the wire to ground and so forth.

The bike will start if I put a screw driver across the starter solonoid terminals so its not the battery. I cleaned up the starter button contacts but when I press the button all it does is turn off the headlight. It's as though no power is reaching the starter.
One other thing that is different is that when I pull in the clutch to change gear when riding the neutral light comes on.

Did you ever find out what was causing the midrange miss in your bike?

Mine started acting up the last time I rode it; when it got fully warmed-up it was trying to detonate under heavy throttle in the midrange so I topped it up with some alcohol-free premium. That helped so I went ahead and retarded the timing very slightly and that seemed to eliminate the problem. (So far anyway; it's possible that I may have an igniter or something else going bad, time will tell.)

The neutral light flashing usually means a diode has been damaged. I think it is in the headlight housing. First, though, you might want to check to make sure all of the connectors under the right side cover are properly plugged. When you tilted the engine, you may have unplugged one of them. Probably a long shot, but worth a look.

oilheadron wrote:Did you ever find out what was causing the midrange miss in your bike?

Ron, I'm pretty sure it was the float levels. I should be able to confirm in a few days.

spencer wrote:The neutral light flashing usually means a diode has been damaged. I think it is in the headlight housing. First, though, you might want to check to make sure all of the connectors under the right side cover are properly plugged. When you tilted the engine, you may have unplugged one of them. Probably a long shot, but worth a look.

I had disconnected the 3 couplings but they went back together fine. If the diode is bad does that stop the starter button from working? Is there a way to bipass the diode?

ajs350 wrote:I had disconnected the 3 couplings but they went back together fine. If the diode is bad does that stop the starter button from working? Is there a way to bipass the diode?

The diode is only to keep the neutral light from flashing when you squeeze the clutch. It should not stop the starter button from working. I still suspect that one of your connectors has an open connection. If I have time, later, I will look at the schematic and see if I can make any sense out of your symptoms.

Looking for something else i cam across a thread with some small similarities.
...the kill switch and the neutral light are in the same line...
viewtopic.php?f=21&t=5426&p=38954&hilit ... urn#p38954

If you have a volt meter, you can do some checking. At the starter solenoid, There should be two smaller wires. One should be Yellow/Red, and the other should be Green/Red. Measure the voltage between them when the ignition is turned on and you are pressing the Start button. If you see about 12 volts, but the solenoid does not click, then your solenoid is probably toast.

If not, measure between the Yellow/Red and ground when you press the start button. If you measure 12 volts there, your start button switch is OK, and power is getting to the solenoid.

If you don't see 12 volts there, follow that Yellow/Red lead through two connectors to the start switch. Check for voltage on each side of the two connectors, with one meter lead connected to the connector, and the other to ground, while pressing the start button. If you see voltage on one side, but not the other, that connector is your problem.

If there is no voltage on the Yellow/Red lead, between the switch and the first connector, your start switch may be bad. Check the voltage on the Black lead from the switch. If it is 12 volts, but nothing on the Yellow/Red lead, while pressing the button, then your switch is bad.

Check the voltage across each connection in the connector closest to the starter solenoid while pressing the start button. Connect your voltmeter to both Yellow/Red leads and if you see 12 volts, that connection is bad. Connect to both Green/Red leads, and if there is 12 volts there, that connection is bad.

If everything is plugged correctly, and the neutral light comes on when you squeeze the clutch, and not in neutral, then the diode is probably shorted. That would not prevent you from cranking the engine. If the diode is open, then you could crank the engine only if you squeeze the clutch. I think that diode is in the headlight housing. The diode's only real purpose is to keep the neutral light off when you squeeze the clutch while in gear.

I am basing all of this on my schematic for a '79. Other years could be different colors, but I doubt it. I'm not actually looking at the bike, but just the schematic. Without looking at the bike, I am not sure exactly where each connector is. I hope that by following the wire colors, you will find the right connectors. Tomorrow, I will look at my CBX to see if what I have told you is actually reasonable. Maybe it is difficult to get at one or more of those connectors. There are a few other things you could check, but I think that if you can check everything I have told you about, you will find your problem. Please let us all know if you figure it out. Good luck to you.

Spencer:
I think you have it exactly right. Great explanation. Not sure if Ross tried pulling in the clutch to start, but now that you've reminded me, that is how I've seen the diodes fail. I think with your explanation he'll get it figured out.

Dave

Spencer: We need a "Hats off" smiley

spencer wrote:If you have a volt meter, you can do some checking. At the starter solenoid, There should be two smaller wires. One should be Yellow/Red, and the other should be Green/Red. Measure the voltage between them when the ignition is turned on and you are pressing the Start button. If you see about 12 volts, but the solenoid does not click, then your solenoid is probably toast.

Spencer, thanks for the detailed post.
I took all the connections apart in the headlamp as well as the switch and cleaned everything up and reconnected.
With my volt meter in the back of the coupler closest to the solenoid I now get 12v when I press the starter button but no cranking so it looks like my solenoid is shot.

Ross:
Your diode and solenoid are on the way this AM. Hope that all works for you.

Dave

daves79x wrote:Ross:
Your diode and solenoid are on the way this AM. Hope that all works for you.

Dave

Dave, thanks for all the e-mail help and for loaning me the parts. I really appreciate it. Ross