1983 gs750es Push start doesn't work, no spark on spark plugs but everything works

[salty_monk]

Yeah I notice the rev guage goes erratic when I was riding and I pass 6rpm it will just go everywhere and sometimes even loose its accuracy like running 30 mph on 3rd gear but the rev guage is at 7k rpm or 8k rpm it doesn't match the rev of the engine

Yep that's the symptoms. You can try melting the solder on the back of the board to see if it fixes it (dry joints) but I haven't found anyone with a reliable fix. I ended up fitting a Koso digital unit instead.

[Guest]

Yep that's the symptoms. You can try melting the solder on the back of the board to see if it fixes it (dry joints) but I haven't found anyone with a reliable fix. I ended up fitting a Koso digital unit instead.

Not worried with that too much I'm going to replace it anyway

[Guest]

What you did proves that SOMETHING is wrong - electrically (as opposed to a problem with solenoid itself).
To further narrow it down, Lets try what you did again, but this time, have the black meter lead on the battery negative (instead of solenoid mounting bolt). If do get 12vdc that way, this will make us suspect a problem with the solenoid grounding.

Report back to us.

Did that, 0 voltage before and when pushing the starter button.

So I have the positive lead meter wire on the positive thin wire on the selenoid and the black meter wire to the negative of the battery made sure contacts are good when I pressed the starter button, zero voltage, tried turning the key off and on and toogle the kill switch a few times, still no voltage

[bwringer]

run a ground wire from one of the selinoid mounting bolts directly to the battery negative

This thread has become a complete mess, but the first reply from Chuck had the most likely problem and solution.

The solenoid sits on a mounting plate. There was a black ground wire with a white stripe connected to this plate from the frame when the bike left Hamamatsu.

However, this ground wire is often disconnected, gone, removed, or damaged. Thus the solenoid does not have a ground connection and cannot function.

[Guest]

This thread has become a complete mess, but the first reply from Chuck had the most likely problem and solution.

The solenoid sits on a mounting plate. There was a black ground wire with a white stripe connected to this plate from the frame when the bike left Hamamatsu.

However, this ground wire is often disconnected, gone, removed, or damaged. Thus the solenoid does not have a ground connection and cannot function.

Did that already nothing happened. Added a ground wire connected to the selenoid to battery negative, same thing no voltage no nothing,

[Guest]

That is because you have a plastic body solenoid that can't be grounded. Did you check the wire crimps from the plug to the solenoid to ensure one of the crimps is not good or the connector broken under the shrink sleeve. That would cause your problem. Just rewire it where the solenoid is cobbed to the solenoid wires unless you put a proper solenoid on the bike. It worked before so look at the simple things people miss. If shorting the two main terminals of the solenoid does not spin the starter motor or there is no voltage going to a main terminal you have an entirely different problem.

[Guest]

That is because you have a plastic body solenoid that can't be grounded. Did you check the wire crimps from the plug to the solenoid to ensure one of the crimps is not good or the connector broken under the shrink sleeve. That would cause your problem. Just rewire it where the solenoid is cobbed to the solenoid wires unless you put a proper solenoid on the bike. It worked before so look at the simple things people miss. If shorting the two main terminals of the solenoid does not spin the starter motor or there is no voltage going to a main terminal you have an entirely different problem.

Yeah I've check the wire crimps their fine. As for the selenoid it's just a jacket I've removed it tried grounding that too, nothing, but shorting the selenoid works it turns the starter motor but pushing the starter button doesn't

[Redman]

.....
Checked it had the positive on the solinoid and negative on the battery have the kill switch to run it shows 12v when I press the start button no click on the solinoid and no voltage change, same when I put it on the negative on the selinoid

......
So I have the positive lead meter wire on the positive thin wire on the selenoid and the black meter wire to the negative of the battery made sure contacts are good when I pressed the starter button, zero voltage, tried turning the key off and on and toogle the kill switch a few times, still no voltage

I am having difficulty helping here.

[Guest]

I am having difficulty helping here.

Sorry disregard this part "Checked it had the positive on the solinoid and negative on the battery have the kill switch to run it shows 12v when I press the start button no click on the solinoid and no voltage change, same when I put it on the negative on the selinoid
"

[Guest]

I am having difficulty helping here.

I have the positive meter wire connected to the positive thin wire on the selenoid and the black meter wire to the negative of the battery made sure contacts are good when I pressed the starter button, zero voltage, tried turning the key off and on and toogle the kill switch a few times, still no voltage

[Redman]

Your recent post:

I have the positive meter wire connected to the positive thin wire on the selenoid and the black meter wire to the negative of the battery made sure contacts are good when I pressed the starter button, zero voltage, tried turning the key off and on and toogle the kill switch a few times, still no voltage

Thanks for clarification.
So NOT getting any voltage to the solenoid when push the starter button. My suggestion then is like said in post 24............

...
. If no voltage when press the start button, well, need to check and see where do have it and where are loosing it.......

The circuit is: Ignition fuse, to kill switch, then to starter button (and ignition coils), then to clutch interlock, then to solenoid, (and solenoid is grounded thru its mounting to battery box).

Check for voltage at the IGNition fuse.
Check for voltage at the kill switch, and after the kill switch (if no voltage at any of those, that most likely is your no-spark problem too)
Check for voltage at and after the start button. To get to any access to any of the kill switch or starter button will need to disassemble the right hand controls. Or if you have a schematic to identify the wire colors, can maybe find the wires in a connector, they should all be in one connector. Or we can skip that for now, ju,st check for voltage at the IGNition fuse, skip the kill swtich and start button for now, and work our back up from the other way.
Next in the circuit (and the last thing before the solenoid) is the clutch switch (called "interlock" , on the schematic), that you say is bypassed on your bike, but you can find the connectors for it (you mentioned the wire colors before). On models I am familiar with (80-82 Gs) the connectors are in the headlight shell. Find those connectors (individual connector per each wire).
When you find the clutch switch wires, it can be confusing since there are four wires all the same color (if clutch switch remains and is stock). One from starter button, one to the clutch switch, one from the clutch switch, and one to the solenoid. One way to identify which is which is that the two for the clutch switch come from the harness of only two wires that goes to left controls.
If the switch is bypassed like you say, the connector from the start button should be connected to the one to the solenoid (and the two connectors from the switch left loose or removed).
Tell us what you find there.
.
If only two wires. THe one from the starter button should have voltage when press the starter. If not, then need to better check the Ignition fuse and the kill swtich and the starter button.
ANd the one to the solenoid should have continuity to the solenoid, and jumping power to it should make the solenoid click.
.
Tell us more what you find.

[Redman]

Also:
I would suggest that anytime when get no voltage on meter, when/where you would expect to be voltage, it is a good idea to then check your meter (and negative connection) by putting the meter red to battery positive (or some other good positive that have checked recently) to see meter read the voltage. That proves meter is setup properly and is working and you have a good connection on meter black probe. THen again putt meter red lead back to the place you were checking, and if still shows no voltage then/ there, well, then you have some confidence that actually is no voltage there.

[Guest]

Your recent post:

Thanks for clarification.
So NOT getting any voltage to the solenoid when push the starter button. My suggestion then is like said in post 24............


The circuit is: Ignition fuse, to kill switch, then to starter button (and ignition coils), then to clutch interlock, then to solenoid, (and solenoid is grounded thru its mounting to battery box).

Check for voltage at the IGNition fuse.
Check for voltage at the kill switch, and after the kill switch (if no voltage at any of those, that most likely is your no-spark problem too)
Check for voltage at and after the start button. To get to any access to any of the kill switch or starter button will need to disassemble the right hand controls. Or if you have a schematic to identify the wire colors, can maybe find the wires in a connector, they should all be in one connector. Or we can skip that for now, ju,st check for voltage at the IGNition fuse, skip the kill swtich and start button for now, and work our back up from the other way.
Next in the circuit (and the last thing before the solenoid) is the clutch switch (called "interlock" , on the schematic), that you say is bypassed on your bike, but you can find the connectors for it (you mentioned the wire colors before). On models I am familiar with (80-82 Gs) the connectors are in the headlight shell. Find those connectors (individual connector per each wire).
When you find the clutch switch wires, it can be confusing since there are four wires all the same color (if clutch switch remains and is stock). One from starter button, one to the clutch switch, one from the clutch switch, and one to the solenoid. One way to identify which is which is that the two for the clutch switch come from the harness of only two wires that goes to left controls.
If the switch is bypassed like you say, the connector from the start button should be connected to the one to the solenoid (and the two connectors from the switch left loose or removed).
Tell us what you find there.
.
If only two wires. THe one from the starter button should have voltage when press the starter. If not, then need to better check the Ignition fuse and the kill swtich and the starter button.
ANd the one to the solenoid should have continuity to the solenoid, and jumping power to it should make the solenoid click.
.
Tell us more what you find.

Starter button fixed and no spark is fixed. thanks a lot man if ever we meet a cold one is on me. While checking for voltage on the starter button I accidentally move the yellow green wire and it worked, stripped bit of the wire and solder it back in place and the starter button is working then I traced the wires again going to the fuse box, check the voltage on the ignition fuse, none, traced the wire and found a broken wire only one thread was connected solder that to and put a shrink tube, after that bike is working fine again, really appriciate man.