[Adam_VN800]

I bought a 2003 GZ250 in boxes and have been building it over the months and I have ran into the strangest no spark problem.

The bike turns over (on the starter) horn and all lights work. I have checked and replaced basics such as fuses, battery, spark plug, kill switch and stand switch.

The existing stator in the engine is burned but is reading between 0.1 and 1.5 ohmes. As the stator was burned I replaced it anyway. Brand new stator fitted, same readings but no spark.

I tested the ignition coil working off of a battery so this couldn’t have been the problem. Wiring harness is reading 12.6V all over including up to the CDI, ignition coil, relay and starter relay.
I have replaced the pick up coil twice as it looks like the previous owner has before.

it would be greatly appreciated for any help or ideas.
Thanks

 

[Intruder8]

post electrical diagram and we will tell you something smart. (or stupid). Any electrical problem diagnosing should start with diagram.
If you attach control light to low voltage wire on ign. coil, it should blink.(one of wires)

 

[Adam_VN800]

Thanks for the reply’s it’s really appreciated. Here is a photo of the wiring diagram.

 

[Intruder8]

Current flow:
fuse 3
side stand
stop switch
ign. coil AND ignitor
Ignitor grounds coil to get spark (W wire, I marked it brown)
Ignitor "knows" crank revolutions from sensor attached to generator (blue wires)

1.Turn ign. on and check voltage in all wires, starting from coil, with red arrows AND brown going to ignitor.
2.attach control light to brown and turn starter, bulb should blink.

Most likely voltage doesn't get to ign. coil (fuse, side stand, stop switch etc.)

 

[Critter]

And check all your grounds (earth's)

 

[Intruder8]

And check all your grounds (earth's)

Updated diagram according to Critter (read what he said)
Black marked wire
BTW, when I bought dead bikes, I had to open and clean bunch of switches: horn, clutch, turn, side stand, stop. It is no fun job, but better than buying new ones.

 

[Adam_VN800]

Thank you for all your help so far! Here’s an update.
So there is a good physical earth to the frame. (Negative terminal is bolted straight to the engine, contact to the frame through engine bolts) Also all fuses in the fuse box are intact.

I put a multi meter to the B/W wire to the igniter from the battery, reads 12V.
G and Bl wires from the stator to the igniter is 12V.
O/W wire from the igniter to the ignition coil is 12V...
I have bypassed the stand and clutch kill switches by connecting the wires together. I know they work as the starter would not even turn over with the GZ models. The same goes for the main engine off switch. I have double checked this by disconnecting stand sensor and clutch sensors and the starter DOES NOT turn over, with the wires connected the starter does turn over. I have yet to check the ignition switch wires to the igniter/CDI.
I will keep everyone posted, thanks again guys!