CB750 scrambler project
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This is the confusion I have , electrics are not my strongest point.
The manual says the yellow/blue wire goes at the top connector on both coils...
The coils are not handed so the green terminal is at the top on one side and black at the bottom when installed.
That's a what's confusing me
I'm still waiting for the new plug caps to try.I'm also not sure if I need to loop the sidestand indicator light as I removed it... I'm pretty sure it just piggybacks
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If it’s connected to the ignition it could be the cause of your problem, specially if you’re neutral lights not working...
Do you think that's the problem looking at this?
To me it looks like if the neutral light is on (which it is) it should start.
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So it looks like according to the diagram that the G/W wire needs to be tied to Earth if you want to bypass the side stand switch. The Y/Bl wire can just be taped up. I.E. don't complete the circuit for that.
@Calum I have the sidestand switch, all plugged in. Only the indicator light isn't connected. Does that affect it? Cheers.
Also still confused on the wires to the green or black connectors on the coils.
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@Calum that's what I'm thinking but if in neutral then it shouldn't Matter ,?
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I can’t get my head round the diagram at the mo. There are a lot of differences from what I know. What about the diode (number 7) condition?
I know that the live wires on the coils will only affect spark timing if wrong, they should still spark. So I’m guessing that the problem is with the side stand, neutral, cutout circuit somewhere, if there’s no spark still...
Sorry I can’t be more help at the mo’. Too many brewskies!🤪 -
I can’t get my head round the diagram at the mo. There are a lot of differences from what I know. What about the diode (number 7) condition?
I know that the live wires on the coils will only affect spark timing if wrong, they should still spark. So I’m guessing that the problem is with the side stand, neutral, cutout circuit somewhere, if there’s no spark still...
Sorry I can’t be more help at the mo’. Too many brewskies!🤪@SpookDog yes it's a crappy diagram, I assume the second bulb is the neutral one.
I've never had a diode go wrong on anything but might test it.
I think it's the side stand ... I'll do more tests when the plug caps come.Thanks
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I can’t get my head round the diagram at the mo. There are a lot of differences from what I know. What about the diode (number 7) condition?
I know that the live wires on the coils will only affect spark timing if wrong, they should still spark. So I’m guessing that the problem is with the side stand, neutral, cutout circuit somewhere, if there’s no spark still...
Sorry I can’t be more help at the mo’. Too many brewskies!🤪@SpookDog I think if I try to crank the engine over (on the starter motor) in gear but with the clutch switch pulled in... That would also prove if the silicon diode is faulty
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@SpookDog thanks.. I tested the resistance and compared it to my spare one, seemed fine. I'm pretty sure it's the sidestand circuit....
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I recon it is as well. I’d connect the side stand and clutch switch stuff all up, put it in neutral and try it with the clutch pulled in.
With the coil connectors, I’d try one ‘one way’ and the other the ‘other way’ if that makes sense? One of them should spark. Once they are sparking it’s easy to figure out which is the outer banks and which is inner...
Good luck my amigo! -
I recon it is as well. I’d connect the side stand and clutch switch stuff all up, put it in neutral and try it with the clutch pulled in.
With the coil connectors, I’d try one ‘one way’ and the other the ‘other way’ if that makes sense? One of them should spark. Once they are sparking it’s easy to figure out which is the outer banks and which is inner...
Good luck my amigo!@SpookDog pulling my hair out,
All the diode does looking at the diagram is. When the stand is down and the bike is in gear, it won't start unless the clutch is pulled in .... But surely is shouldn't allow the starter motor to operate as that alone can knock the bike off the stand,Also should the side stand light only come on when stand is down ( in gear )or all the time including neutral
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Trouble is it could be any one of these switches:
Key Ignition
Handlebar kill
Sidestand
Clutch
NeutralOr these parts:
Pulse generator/pickup
FusesOr just a break in a wire.
I’d start off by checking fuses, then doing continuity checks on the switches, then the wires
Check for volts at the coloured coil wires, volts at pick up while cranking the starter -
I think I know the issue. The pulse generator had a load of oil in there. Doesn't put out 0.7v
When I crank the engine I can feel pressure of air blow past the crank seal
the crank seal itself might not be broken but the pressure bypasses it.
I can't see this seal on fowler's diagramsAll cylinders seem to have good compression so can think why the crankcase has so much pressure. Unless it's a blocked pcv.... Not sure if they have valves ....
Lots of ball aches...
I couldn't really test any of this before fitting the engine all together.
