Shake Down Break Down !!!

Sidestand switch faulty?

 

Timing sensor or ECU?

 

if it's your Superlight your talking about then sidestand switch only puts a light on on 'dash' but shorting out wouldn't help if leads are manky. Could be so many things from symptoms but (despite you saying one spark) i'm going to go with corrosion in plugs between regulator and alternator if it has just cut spark to both cylinders. Even on this note, I know Mr AA man has attended but std spark generated was never the best during churning and hard pressed to see one clearly if the sun is out. Did he do a voltage test on battery as a crude indication of state of charge? If you are convinced it's electrics then it's a check on all ignition related wiring and components which won't take long on yours. Have spare exciter boxes to try if you need them Simon. I think you drained tank and checked for water/corrosion didn't you? Does pump pitch sound normal?

 

what's state of play now Si - got it back home and running? If he had checked voltage and it was sub 12v then could have been a clue to what's going on. New battery? I would be all over connections like a dose of salts if it's been stood and not used 'regularly recently'. Favorite is white corrosion on any of the three regulator plugs - two yellow one black from memory - like large bullet connectors. If the reg doesn't get or send correct messages due to this then several symptoms can develop as the alternator 'argues' with it. As said, this is only off top of head as so many other things could cause similar symptoms.

 

Chris is right about the sidestand switch and wiring.

Change the plugs for NGK then check the spark.

If both sparks are OK, the pickups are probably OK as well......You can check the resistance and continuity for the pick-ups and coils, but disconnect the wiring first.

Also, the HT leads can be very loose in the coils and caps.........I changed the leads and caps on mine.

My immediate thought was carbs, pilot circuits blocked, because the bike has been standing and float bowl crap could now have shifted.

Voltage check the alternator output.

Reg/rec could be playing up.....is it OEM or the replacement RR51? (Look for a label or something on it)......Sometimes people are cack-handed at doing the new wiring for the RR51.

 

Basic, I know but have you checked the kill switch?
On my SS, you could turn the engine over with the kill switch on but it wouldn't fire.
Also on my SS, when it cut out on one cylinder, it turned out to be a damaged pick up caused by a loose alternator nut, a common problem on these bikes.

 

If you have the meter out, this may help.....


COIL HV 3700 Ohm +/- 10%
HC VC

COIL LV 0.34 Ohm +/- 10%
HC VC

PICK-UP 100 Ohm +/- 5%
HC VC

CDI ignition systems,trouble shooting,how do they work?

There appears to be a lot of misunderstanding and confusion about the capacitor discharge ignition systems used today on most small IC engines.The reason for the popularity of CDI systems is that they are easier to miniaturize than the old fashioned but rugged magneto setups as found for instance on the B&S lawn mowers.They also dispense with breaker contacts which will wear out,making a maintenance-free ignition system possible (at least in theory)
CDI is a successor to the magneto based ignition systems evolved a century ago by Bosch of Germany (Their logo still shows a magneto).It was a self-contained system,no batteries were required and it was used exclusively until these became common with the advent of electric starters).Magnetos were big and expensive and lost out to cheaper battery ignition,but held their own in motorcycles due to good high speed performance,They were standard in the smaller 2 strokes as flywheel magnetos/generators until CDI systems became competitive with the advent of solid state electronics
In a CDI ignition system,a storage capacitor is charged to a high voltage (a few hundred volts) by the flywheel charging coil and, at the proper moment quickly discharged into the primary winding of the ignition coil,which is actually a stepup pulse-transformer.The secondary output is a short very high amplitude pulse which fires the spark plug.All these events take place during each engine revolution.The charging coil is usually located inside the flywheel,if there is room for it, but if the flywheel doubles as a cooling fan it has to be located outside.The spark timing is controlled by a small trigger coil located in close proximity to the flywheel which generates a low voltage pulse (actually two, a positive and a negative one), as the fly wheel magnet passes by.The circuitry in the CDI unit uses this pulse to close a solid state switch (usually a thyrister) to discharge the storage capacitor into the ignition coil primary and generate the high-voltage pulse at the secondary to fire the plug.This capacitor has previously been charged to a high voltage with the high energy pulse induced in the charging coil by the flywheel magnets.All these events take place every revolution.
Both the pick up coil and the power coil have two wires connected to them, one side of each goes to ground (usually coded black),they may be grounded internally in the magneto or connected together and brought out as a single wire and grounded outside or connected to a ground connection on the CDI unit.The two live outputs (charger coil output and trigger) are connected to the CDI unit.They can be identified by disconnecting them from the CDI and checking the resistance to ground with an Ohm meter.The trigger coil has low resistance,the charger coil higher (a few hundred Ohms typically).Both outputs are ac. signals!!,the charger output typically in the range of 100 V ac. DC measurements of this signal are MEANINGLESS and deceiving !,all they measure is the degree of asymmetry of the ac output,not the actual amplitude.Even simple multimeters have an ac position.The charger output is an unhealthy signal that could kill you under the right circumstances,sit on a wet saddle and grab the bare "white lead" for kicks. while riding around.This is not all that likely of course,but the output of the charger coil should be treated with respect.
I have never set eyes on one of these Chinese 2 stroke engines,so as far as color coding goes bear with me,I have concluded that the "tormentor" "white wire" is connected to the charge coil output and the "blue wire" is connected to the trigger coil.Shorting either one to ground will disable the ignition and stop the engine,in the first case the storage cap does not get charged,in the second it does not get discharged.Opening up the connections between these outputs and the CDI unit accomplishes the same thing,I would prefer shorting to ground esp., for the low level signal from the trigger output,a long lead would be connected to the CDI trigger input and a spurious signal could conceivably blow up the input device.Shorting them to ground does not hurt anything and is safer.I would use grounding connections going back to the engine ground and weather proof the switch and I would leave the output of the charging coil alone.It is probably possible to power other devices from the output of the charging coil,I think it could power a sophisticated high voltage low current dc circuit to minimise the drain on the coil feeding an efficient power convertor to convert this high voltage (50 V plus) to 12 or 6 volts power at higher currents.
Trouble shooting hints.Caution ,if testing for spark ALLWAYS have a plug connected with the shell grounded,never ever test with an open plug lead, you may destroy the ignition coil.
1) Disconnect leads going to kill switch (shorting mode hookup!) and try starting engine (Figure out how to stop it in case it runs) .
2)The charge coil and trigger coil are fairly robust devices and not likely to fail,measure resistance to ground (disconnect from CDI),if shorted or open circuit,they are defective or leads bad.
3) Ignition coil,disconnect from CDI if possible,measure resistance to ground of primary,should be a few ohms,measure secondary resistance to ground, should be a few thousand ohms.Caution: High resistance may be due to high resistance HT lead to plug!.Not easy to check unless you can get at coil output directly.
4) CDI unit,probably implicated if other tests OK
I hope that this post has shed some light on the mysteries of CDI ignition systems

 

Remind me why you posted Simon?