No spark.. stumped

[MaliZ]

i got an 89 gpx the other day, first thing i noticed was it only ran on one cylinder unless you gave it a fair bit of throttle so i pulled the carbie off to find a jet was missing, thats fixed and back on now but when i tried starting it it was dead, no spark. everything else is working as in dash, lights, starter, etc but no spark. any ideas where to start to figure it out? are there certain points i can check with a multimeter to narrow down what i should be looking for?

[EMSRacer07]

did you change out the old spark plugs? they could have fouled or gotten wet

[MaliZ]

Originally Posted by EMSRacer07

did you change out the old spark plugs? they could have fouled or gotten wet

i havent pulled them out because it was running the day before i did the carbie, but it cant be plugs because i found out it had no spark by unplugging the leads and putting two new ones in and earthed them out and turned it over, neither have spark, if i do that on my other gpx you can see spark clear as day instantly, cheers for the reply

[EMSRacer07]

Originally Posted by MaliZ

i havent pulled them out because it was running the day before i did the carbie, but it cant be plugs because i found out it had no spark by unplugging the leads and putting two new ones in and earthed them out and turned it over, neither have spark, if i do that on my other gpx you can see spark clear as day instantly, cheers for the reply

the ignition box working? that might be fried or the coils. Would check to see if any power was going to the coils or to the ignition box.

[MaliZ]

Originally Posted by EMSRacer07

the ignition box working? that might be fried or the coils. Would check to see if any power was going to the coils or to the ignition box.

i jjust checked both coils and they put out 0.08V for the first half of a second then nothing as it kept winding over, and assuming the ignition box is the one on the left side at the rear and not the one with the fuses that only had 0.05V going to it with the ignition turned on and didnt change when i wound it over

[EMSRacer07]

Originally Posted by MaliZ

i jjust checked both coils and they put out 0.08V for the first half of a second then nothing as it kept winding over, and assuming the ignition box is the one on the left side at the rear and not the one with the fuses that only had 0.05V going to it with the ignition turned on and didnt change when i wound it over

yeah ignition box is on the left side. Could be that. Idk how you could test those.

[MaliZ]

Originally Posted by EMSRacer07

yeah ignition box is on the left side. Could be that. Idk how you could test those.

i have a 92 gpx for parts plus a big box of random parts, tried 3 different ignition boxes and no change, might resort to pulling old wiring loom out and putting everything from the spare bike in it, i know that one has spark

[Motofool]

Check the magnetic pick up sensor; the proper gap is important.

This article may help:

http://www.dansmc.com/electricaltesting.htm

"The ignition module is a component of the safety switch circuits, and will not operate unless certain safety switch conditions are met."

http://faq.ninja250.org/wiki/Underst...afety_switches

http://faq.ninja250.org/wiki/Wiring_...s_%26_diagrams

[Lychee]

worked prior to carb being removed.
no spark from both leads
all other electronics work
known good ignitor does not work on this bike

have you checked for a broken ignitor fuse?

[alex.s]

check the input going into the main coils. also check main coils and crank pickup resistance.

[EMSRacer07]

check grounds too. hmm sounds like a break in the lines or fuses

[MaliZ]

Originally Posted by Lychee

worked prior to carb being removed.
no spark from both leads
all other electronics work
known good ignitor does not work on this bike

have you checked for a broken ignitor fuse?

where is the ignitor fuse, im used to working on cars and dont quiet know my way around the whole bike yet? thanks

[MaliZ]

Originally Posted by alex.s

check the input going into the main coils. also check main coils and crank pickup resistance.

checked main coils resistance which was 04.7 and the two wires coming out of the motor from the crank pick up was 125.6,

[alex.s]

125ohms on the pickup should be good. you'll have to look up the proper specs on the mains. is there any power going into the main coils? check the voltage going to the main coils... might need an analog gauge or an oscilliscope since its pulsed

[MaliZ]

Originally Posted by alex.s

125ohms on the pickup should be good. you'll have to look up the proper specs on the mains. is there any power going into the main coils? check the voltage going to the main coils... might need an analog gauge or an oscilliscope since its pulsed

all i have at the moment is a multimeter, i know it would be impossible to get a consistant reading but it would come up with something and jump all over the place from it pulsing if there was power going to it wouldnt it? or would it just read 0.000? cause i checked and expected to see something even if its random flashing numbers but it was a constant 0.000

[MaliZ]

Originally Posted by Motofool

Check the magnetic pick up sensor; the proper gap is important.

This article may help:

http://www.dansmc.com/electricaltesting.htm

"The ignition module is a component of the safety switch circuits, and will not operate unless certain safety switch conditions are met."

http://faq.ninja250.org/wiki/Underst...afety_switches

http://faq.ninja250.org/wiki/Wiring_...s_%26_diagrams

cheers, actually helped me understand what im working with a bit better

[alex.s]

it really depends on the multimeter, but you should see something. if you are really seeing nothing while cranking then i would think either the wiring going to the main coils or the CDI is bad

[MaliZ]

Originally Posted by alex.s

it really depends on the multimeter, but you should see something. if you are really seeing nothing while cranking then i would think either the wiring going to the main coils or the CDI is bad

yeah, tried two other cdi boxes (if thats the black boxon the rear left hand side of the bike) and there was no change at all. guess ill have to follow the wires back

[alex.s]

if your cdi is good, and it is getting power, your pickup coil is good and is really pulsing, but you get no fires to the main coils, i would think that there is something wrong with the wiring going to the coils. either a disconnect between the cdi and coils or a ground issue

[MaliZ]

Originally Posted by alex.s

if your cdi is good, and it is getting power, your pickup coil is good and is really pulsing, but you get no fires to the main coils, i would think that there is something wrong with the wiring going to the coils. either a disconnect between the cdi and coils or a ground issue

just turned the igniton on and no power is going to the cdi, unless 0.03V counts as something

[Lychee]

Originally Posted by MaliZ

where is the ignitor fuse, im used to working on cars and dont quiet know my way around the whole bike yet? thanks

F3 in the junction box.

http://faq.ninja250.org/images/a/a4/...matic_-_R4.pdf

[Motofool]

Just for testing the coils (which are nothing more than transformers):
At least in theory, each coil should generate one spark if fed with battery voltage and then suddenly disconnected.

http://en.wikipedia.org/wiki/Ignition_coil

"When the contact breaker closes, it allows a current from the battery to build up in the primary winding of the ignition coil. The current does not flow instantly because of the inductance of the coil. Current flowing in the coil produces a magnetic field in the core and in the air surrounding the core. The current must flow long enough to store enough energy in the field for the spark. Once the current has built up to its full level, the contact breaker opens. Since it has a capacitor connected across it, the primary winding and the capacitor form a tuned circuit, and as the stored energy oscillates between the inductor formed by the coil and the capacitor, the changing magnetic field in the core of the coil induces a much larger voltage in the secondary of the coil."

[alex.s]

Originally Posted by MaliZ

just turned the igniton on and no power is going to the cdi, unless 0.03V counts as something

well thars ur problem
Posted via Mobile Device

[MaliZ]

And the conclusion is a wire broke loose inside the kill switch, sucks how sometimes simple things take a while to work out, but id only just replaced the previous broken one and didnt expect his one to fault in a matter of 2 weeks. unlucky

[alex.s]

lol we disabled @Havok's kill switch for this very reason