chinese scooter

[mick_benson]

hi all i'm after some help, i picked up a little 50cc twist and go chinese thingy, dont run, no spark,
have checked wiring, all ok
replaced CDI
replaced COIL
have power to coil but still no spark any ideas ???

[Snowy]

hi all i'm after some help, i picked up a little 50cc twist and go chinese thingy, dont run, no spark,
have checked wiring, all ok
replaced CDI
replaced COIL
have power to coil but still no spark any ideas ???

HT lead/plug?

Has the battery enough juice to make a proper spark?

[mick_benson]

HT lead is part of the coil, plug is new,
battery via jump leads off bigger battery but still no spark

[njl]

whatever triggers the spark, crank sensor perhaps

[Snowy]

Does the engine turn?

Kill switch?

Sidestand switch? (If it has one)

Is it in gear?

Sorry, can't think of much else.

[mick_benson]

engine turns, on kick start electric start not working,
no kill switch
no stand switch
no gears
think i need a bigger hammer :-)

no sure where else to test (whatever triggers the spark, crank sensor perhaps)??

[wheelers]

one of the brake switches not working.
low battery.
bad earth.
did you replace the cdi with a new one?

[mick_benson]

yeah new cdi, new coil, new plug

[Harry87]

Condition of battery terminal posts? Cracks, bad contact etc..

[Jon_W]

Could be the grounding of the CDI, engine or coil. Check all first.

To check the CDI and crank sensor.

What you need to do is put a moving coil meter such as an AVO onto the input of the coil (dissconnect the coil) and crank the engine over. There should be a 60V+ spike in the voltage out of the CDI. If there is no spike, I'd check the crank sensor. If there is a small spike thn I'd suspect the CDI.

To check the sensor directly you will need to find the signal wire and the ground wire and put the moving coil between tose two set to 10V.

Don't try this with a digital meter, you'll see nothing.