New here. Depressing issue. No spark on one side :(

[249cc]

Hey everyone. I hate that my first post is a cry for help but I'll be sticking around afterward.

My 02 ninja 250 was riding really sluggish. Wouldn't go past 40 in any gear. I read a ton of FAQs and articles before I decided to post. I checked my carb, my air box...basically everything but the sparkplugs. When I finally checked those, I realized my left plug wouldn't spark (I grounded it against the valve cover). I tried everything. I swapped and tested new plugs, swapped plug cables, and even swapped my coils from each side. Both coils are working but I'm still not getting spark from that left side. I even bought a multimeter to test the coils. They're within specs.

What more can I test? I'm tearing out my hair.

A couple notes:

I have the bike sitting now with no tank, gauges, or fairings as I was working on a street fighter build. It was working before. I thought it might have something to do with me removing the gauges as that was the only electrical modding I've done.

[249cc]

My progress.

[Jiggles]

Maybe change your name to 124.5cc and call it a day?

[lgk]

did you check everything against the wiring diagram?

[FvnnyL3tt3r1ng]

Engine Compression!

I'm looking at the schematics and it says there is a green wire that comes out of the "ignitor" to ignition coil 1, and a black wire that goes to ignition coil 2 from the ignitor. Also, a red wire comes from your right handlebar switches (start button and engine stop switch) to both ignition coils in parallel. Check those out to see if they have been damaged from heat or anything.

Just curious- what happens when you take off your odometer? Or do you just tuck it somewhere?

[DaBlue1]

Originally Posted by 249cc

....A couple notes:

I have the bike sitting now with no tank, gauges, or fairings as I was working on a street fighter build. It was working before. I thought it might have something to do with me removing the gauges as that was the only electrical modding I've done.

Do you have any other electrical wires attached the the coils? If so, remove them and test the spark output again.

[alex.s]

it sounds like right now you dont know if the cdi is even sending current to that coil... you tested the coils... check and make sure power is actually getting to both coils then check and make sure power is getting sent out the plug wires

[FvnnyL3tt3r1ng]

Originally Posted by alex.s

it sounds like right now you dont know if the cdi is even sending current to that coil... you tested the coils... check and make sure power is actually getting to both coils then check and make sure power is getting sent out the plug wires

This is true, you can get a clamp-type ammeter for about $50-80 to quickly check if there is current flow from part to part.

[249cc]

Thanks for all your input. I'll reply to each of you when I get home.

All I have is a multimeter I literally bought today to test the ohm reading of the two coils. I'm pretty certain it's not the coils. What and how do I test using this multimeter beyond what I've done? Im not good with it so a detailed explanation would be greatly appreciated.

[n4mwd]

Make sure you don't have Champion plugs in there. You'll have nothing but headaches if you do. The bike does not like them.

I'm curious how you managed to swap plug cables given that they are molded into the coil.

Anyhow, use a very small 12V light bulb to measure the voltage going into the coil while its running. You should see it flickering.

[alex.s]

put the multimeter on DC volts 15, disconnect the coil that isn't firing and instead connect those wires to the multimeter probes. if you see the gauge getting voltage as you crank the bike you know the cdi is trying to power the coil for that cylinder. in which case the issue would have to be on the other side of the coil... the coil itself, the plug wire, the spark plug, or the ground connection going to the head.

if you see nothing going into the coil, it means there is a problem with either the CDI (seems unlikely since its sending power fine to the other coil) or the wiring between the cdi and the coil.

since you replaced the CDI/plugwires, plugs and the other cylinder fires. the biggest target would be the wiring between the CDI and the coil.

[ryan.chin]

Originally Posted by Jiggles

Maybe change your name to 124.5cc and call it a day?

i lol'd

[249cc]

Originally Posted by FvnnyL3tt3r1ng

This is true, you can get a clamp-type ammeter for about $50-80 to quickly check if there is current flow from part to part.

:[ Is it extremely necessary? I already spent $20 I didn't have on a multimeter.

Originally Posted by n4mwd

Make sure you don't have Champion plugs in there. You'll have nothing but headaches if you do. The bike does not like them.

I'm curious how you managed to swap plug cables given that they are molded into the coil.

Anyhow, use a very small 12V light bulb to measure the voltage going into the coil while its running. You should see it flickering.

I think they're NGK or some other brand. I've taken this bike 100 miles one way and it didn't even break a sweat. I've read nasty things about those Champion plugs also.

By plug cables, I meant I swapped the part that attaches directly to the plugs.

Originally Posted by alex.s

put the multimeter on DC volts 15, disconnect the coil that isn't firing and instead connect those wires to the multimeter probes. if you see the gauge getting voltage as you crank the bike you know the cdi is trying to power the coil for that cylinder. in which case the issue would have to be on the other side of the coil... the coil itself, the plug wire, the spark plug, or the ground connection going to the head.

if you see nothing going into the coil, it means there is a problem with either the CDI (seems unlikely since its sending power fine to the other coil) or the wiring between the cdi and the coil.

since you replaced the CDI/plugwires, plugs and the other cylinder fires. the biggest target would be the wiring between the CDI and the coil.

I tried that. On the side that works (right side if you're sitting on it), I disconnected the coil and ran the multimeter on dc voltage. With the kill switch on run and the key in the on position, I was getting 0 volts. When I cranked, it was getting a jump in the 30's or so (if I read it right). I switched sides, removed the cables from the left coil, ran the multimeter without cranking. I was getting 12.5 volts without even cranking. While cranking I got a jump similar to the jump on the right side. Completely puzzled.

Originally Posted by ryan.chin

i lol'd

So did I...after being frustrated a bit.

[alex.s]

The 12v should be coming from the taco meter but you said it's disconnected which means maybe tat wire leading to the dash is shorting out against a +12v somewhere

[n4mwd]

Originally Posted by 249cc

:... I switched sides, removed the cables from the left coil, ran the multimeter without cranking. I was getting 12.5 volts without even cranking. While cranking I got a jump similar to the jump on the right side. Completely puzzled.

Sounds like its shorted to 12V. Does the battery by any chance read the same voltage (12.5V)? Unless you have a really good DVM, you can't accurately read a pulsed voltage.

The igniter could be bad, but its pretty rare. Try disconnecting it and measure the voltage and see if its still 12.5V.

EDIT: Since the left coil is hooked to the tach, what does is it doing when you crank.

[249cc]

Originally Posted by alex.s

The 12v should be coming from the taco meter but you said it's disconnected which means maybe tat wire leading to the dash is shorting out against a +12v somewhere

I wish I knew more about shorting and electronics. I'm not really sure what that means as far as me fixing it.

Originally Posted by n4mwd

Sounds like its shorted to 12V. Does the battery by any chance read the same voltage (12.5V)? Unless you have a really good DVM, you can't accurately read a pulsed voltage.

The igniter could be bad, but its pretty rare. Try disconnecting it and measure the voltage and see if its still 12.5V.

EDIT: Since the left coil is hooked to the tach, what does is it doing when you crank.

The tach is off and I stupidly took the gauges out of the cluster in hope of finding a way to house them in separate gauge buckets (again, for the streetfighter project). I can't tell you what it does since it's completely off the bike and I think I lost some of the screws that fix the wires to the gauges (except of course the speedo cable...but that's there to stay).

Also, I multi'd the battery and it reads 12.5 v.

[alex.s]

I say again... Your wires going to the tachometer are touching things they shouldn't.

[249cc]

Originally Posted by alex.s

I say again... Your wires going to the tachometer are touching things they shouldn't.

Sorry about that. All the wires that would have gone to the gauges are all in a wiring harness connector. If it's shorting, then it must be that the insulation on the cable is shot somewhere else.


I'm going to tear open the electrical tape and remove all the tach wires. That should do it, right?

[alex.s]

I wouldn't go crazy until you know what the problem is.
Disconnect the cdi and coils and check for continuity from the wire going from the cdi to the coil and check it against the positive terminal cable that goes to the battery

Battery should be disconnected when doing ohm or continuity checks so you don't damage your meter

[n4mwd]

Any chance you tightened a nut on the wire and squished it?

The CDI is on the left side. Disconnect both cables and see if you are still getting 12.5V.

Attached is a schematic that might be helpful.

As a side note, its a good idea to save all your parts so that you can restore the bike when selling it later. Naked bikes don't sell for very much.

[249cc]

Originally Posted by n4mwd

Any chance you tightened a nut on the wire and squished it?

The CDI is on the left side. Disconnect both cables and see if you are still getting 12.5V.

Attached is a schematic that might be helpful.

As a side note, its a god idea to save all your parts so that you can restore the bike when selling it later. Naked bikes don't sell for very much.

I'll check that tomorrow. Another note to all. My girlfriend has a fully functional ninja 250 that lives at my house also. I swapped CDI's and it changed nothing.

And thanks for the tip. My front fairings are pretty much after I wrecked. If anything, I could always sell my bike to my girlfriend for parts.

[Motofool]

Important: The red wire goes to the lower tab in both coils.

[n4mwd]

Just so we're clear, this is the thing you swapped:



Did you check for 12.5V on the wire with the CDI disconnected?

[249cc]

Originally Posted by n4mwd

Just so we're clear, this is the thing you swapped:



Did you check for 12.5V on the wire with the CDI disconnected?

I haven't yet. I will after work.

Yup. That's the thing.

I'm really starting to think it has something to do with the tach. The bike was working great until I started taking off things from the front end ,

[FvnnyL3tt3r1ng]

To answer your question about buying the clamp ampmeter: No it is not necessary at all because you have a multimeter that will do the same job just with more fuss. I would recommend you do a continuity test on the wires I mentioned in my above post. GL

[flynjay]

I am going to take a leap and say the #1 coil (the one on the left) is the one not working right?

Take a look at the wiring diagram @n4mwd posted. The #1 coil wire also goes to the tach. If you are reading 12.5 V without cranking then there is a wire shorted to ground somewhere (more than likely at the tach since that is where you were working.

[249cc]

Originally Posted by flynjay

I am going to take a leap and say the #1 coil (the one on the left) is the one not working right?

Take a look at the wiring diagram @n4mwd posted. The #1 coil wire also goes to the tach. If you are reading 12.5 V without cranking then there is a wire shorted to ground somewhere (more than likely at the tach since that is where you were working.

It IS coil 1. And this mess did all start when I removed the gauges. What do I do then? I'm going to take my lunch break and check for continuity from the ignition wire to the coil wire (I'm guessing its the black one), but what am I looking for as far as ohms? And what happens next?

[flynjay]

Originally Posted by 249cc

It IS coil 1. And this mess did all start when I removed the gauges. What do I do then? I'm going to take my lunch break and check for continuity from the ignition wire to the coil wire (I'm guessing its the black one), but what am I looking for as far as ohms? And what happens next?

There are three wires going to the tach (Positive, Ground, Signal). The signal wire is the one that comes from the CDI, but also goes to coil #1.

Check all three wires against ground (measuring resistance). Basically if it reads some value there is a connection there.

Report your findings.

[n4mwd]

Originally Posted by flynjay

... as a quick fix to get the bike running you could run a wire from the negaive side of the coil on the right over to the negative terminal on the left. The CDI on the ninja runs with a wasted spark on the exhaust stroke so both coils actually fire at the same time. Also the CDI actually doesn't send a pulse to the coils, it mearly completes the circuit to ground allowing the coil to fire.

Umm, no, not exactly. It does use a waste spark and fires at roughly TDC for both exhaust and compression with compression being the only one that counts. The pistons are 180 degrees out of phase so you cannot use one pulse to work both pistons. If you do, you'll either accomplish nothing or cause some nasty backfires when the thing fires at BDC on cylinder #1.

Originally Posted by 249cc

It IS coil 1. And this mess did all start when I removed the gauges. What do I do then? I'm going to take my lunch break and check for continuity from the ignition wire to the coil wire (I'm guessing its the black one), but what am I looking for as far as ohms? And what happens next?

Ninjas don't like running around town naked. Buy some used plastics off ebay or craigslist. I got a spare set for my bike for only $50. This problem may be your Ninja rebelling.

[n4mwd]

Originally Posted by 249cc

It IS coil 1. And this mess did all start when I removed the gauges. What do I do then? I'm going to take my lunch break and check for continuity from the ignition wire to the coil wire (I'm guessing its the black one), but what am I looking for as far as ohms? And what happens next?

Make sure you disconnect the CDI when checking for continuity or you will get strange readings.

[Motofool]

Originally Posted by n4mwd

Umm, no, not exactly. It does use a waste spark and fires at roughly TDC for both exhaust and compression with compression being the only one that counts. The pistons are 180 degrees out of phase so you cannot use one pulse to work both pistons. If you do, you'll either accomplish nothing or cause some nasty backfires when the thing fires at BDC on cylinder #1.

Correct:

http://en.wikipedia.org/wiki/Straight-twin_engine

Parallel twin engines with 180 degree crankshaft need separate carburetors and separate ignition systems.

[flynjay]

Originally Posted by Motofool

Correct:

http://en.wikipedia.org/wiki/Straight-twin_engine

Parallel twin engines with 180 degree crankshaft need separate carburetors and separate ignition systems.

I was wrong. I've edited my previous post.

[249cc]

I filmed the voltage tests. I filmed them in case I screwed something up.

https://www.youtube.com/watch?v=jZJC...e_gdata_player

I also filmed the continuity tests but theyre taking a bit to upload. I got no readings on the continuity test


I noticed that when the kill switch is off, I get a low voltage from the battery from both pairs of coil wires. When I flip the kill switch to RUN, the cylinder 1 coil wires put out 12.18 volts while cylinder to stays at 0.02 volts.

I get no ohm readings when I tested the tach wires to ground. I did this by setting one problems to the wiring harness connector for each wire and the other probe to the valve cover.

[alex.s]

@249cc take a photo of the wires that previously led to your tachometer and post it here.

[DaBlue1]

Originally Posted by 249cc

....By plug cables, I meant I swapped the part that attaches directly to the plugs.

Taking off the plugs boots and not putting it back on properly may be a reason no spark is coming across the plug.

[249cc]

Originally Posted by DaBlue1

Taking off the plugs boots and not putting it back on properly may be a reason no spark is coming across the plug.

Pretty sure that isn't it because I've been swapping them for a while one between another and I still only get spark on one side. Even swapped the coils so I don't think it's a bad coil wire.

[alex.s]

umm...

1: bike worked fine
2: gauges removed
3: bike no work

A: cylinder one no go boom.
B: coil one feeds cylinder one,
C: coil one connected to gauges...
D: but gauges removed... wires leading to gauges are........??????????


all signs point to the gauge wires leading to the tachometer. several people have come to the same conclusion.

[249cc]

https://fbcdn-sphotos-b-a.akamaihd.n...80922710_o.jpg

In the second picture you can see the block connectors in the front. No loose wiring.

https://fbcdn-sphotos-f-a.akamaihd.n...42341795_o.jpg

[alex.s]

i see. i was under the impression the gauges were disconnected. what happens when you disconnect the black wire connected to the tachometer

[n4mwd]

For testing here, lets always keep the kill switch set to RUN.

Ok, a quick look at the schematic shows that when the key switch is ON then the red wires to BOTH the coils should have 12V on them.

The other wires, black for cylinder #1 and green for #2, go to the CDI. The black wire also goes to the tach. It is not a ground wire.

IMPORTANT: Disconnect the CDI. The video shows it still connected.

The black and green wires should read identical but not connected. Using the ohms setting on the DVM, check for resistance of each to ground (Engine block or neg terminal of battery).

If it shows low resistance, then you have a short to ground somewhere.

If you forget to disconnect the CDI, the readings are incorrect.