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Weak Spark ?
Posted: Tue Jan 11, 2011 1:57 pm
by maderdog_1024
Ive never been able to get this bandit 400 to run properly and now im on a mission to get it done.
Carbs are off and im about to re-build.
The spark seems weak. Is there any way to boost the spark ?? I read somewhere that coils from a bandit 750 work better ??
Im not 100% sure if my coils are wired up correctly, does anyone know the correct polarity/colours etc.
Cheers
Mike
Re: Weak Spark ?
Posted: Tue Jan 11, 2011 10:01 pm
by Variablevalves suck
Im sure the 750 coils are the same. Near side HT coil feeds cyliders 1 and 4, off side feeds cylinders 2 and 3.
link is to a wiring diagram with colours.
http://homepage.mac.com/mosquito/file/G ... 2-2330.pdf
Re: Weak Spark ?
Posted: Thu Jan 20, 2011 2:51 pm
by maderdog_1024
Can anyone tell me what the voltages should be on the LT side of the coils and across what wires ?
I have just stripped my carbs and boy those o-rings are screwed.
Mike
Re: Weak Spark ?
Posted: Thu Jan 20, 2011 7:10 pm
by maderdog_1024
From another forum;
The sidestand relay sends power to the kill switch. This in turn passes power to the starter button, and the ignitor.
If it is turning, then there's nothing wrong with the Ignition switch, sidestand switch, sidestand relay or kill switch.
That leaves wiring to the ignitor or coils, or faulty ignitor, or faulty signal generator.
To check the ignitor wiring pull the plug from the ignitor and put a meter on the Orange and White wire. You should have 12V there with the ignition and kill switch on.
If you have no voltage there but the engine will crank when you hit the starter button you have a wiring fault.
If you have voltage there you should check the connectors aren't green and rotted. Check also the terminals in the ignitor. Best bet is to take photos of both and post them here.
To check the coil wiring put a volt meter on each of the orange wires feeding the coils. Should be 12v there directly from the ignition switch.
If the terminals look ok you should test the signal generator. The connector you can find by removing the seat and left air cleaner cover. Unplug the connector and measure the resistance of the sensor (brown wire and black with blue tracer wire). The serviceable range is 80-120 ohms.
Do all this and see where you get mate
Okay so I have;
+12V Feed to Ignitor
90ohms on Signal Generator
What I do have though is on the the left hand coil orange and white to earth is 3volts and on the right hand coil orange and white to earth is 0.4volts
Re: Weak Spark ?
Posted: Thu Jan 20, 2011 10:41 pm
by Variablevalves suck
Should be easy to trace the problem. The 12V at the coils is same wire that connects to the ignition switch and that goes through the main fuse, its switched by the relay on the rear sub frame and you will be able to hear it click when the ignition is switched. The relay will have a red that is 12V and then the orange will go 12V when switched.
Re: Weak Spark ?
Posted: Thu Jan 20, 2011 11:02 pm
by maderdog_1024
Could be the relay, as previous owner said he tried a second loom and it had same symptoms. There are also some suspicious looking joints too.
Going to get this thing running tomorrow, im determined now !!
Re: Weak Spark ?
Posted: Fri Jan 21, 2011 2:10 pm
by maderdog_1024
I have shed a bit more light on my problem.
The 12 volt feed to the coils is the same 12v feed that powers the Ignitor. When this is connected to the ignitor it drops to 3volts.
Disconnect it from the ignitor and its back up to 12volts.
So faulty ignitor ?? I now have no spark.
Mike
Re: Weak Spark ?
Posted: Sat Jan 22, 2011 11:22 pm
by M1KE
Faulty Ignitor very likely.
Weak Spark ?
Posted: Sun Jan 23, 2011 2:41 pm
by maderdog_1024
I've heard these can be DIY repaired. Anyone have any ideas ?