Yamaha R1 Forum: YZF-R1 Forums banner
1 - 9 of 9 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
Recently purchased a 2003 R1 w/power commander 3. I was told the bike had sat for a few years. I replaced fuel pump and drained fuel changed oil etc. only to find out I also had no spark. I followed the troubleshooting manual and got no where. Here is where I am a little confused. I am getting over 12 volts at the head of the harness on the hot wire when the key is on and kill switch is on. I was under the impression the second wire is a ground wire? But if I connect a light probe tester to the positive on battery and to the second wire I get nothing doesn’t matter if bike is cranking or etc. I also get no volts or anything coming from the wire either. I check tolerances on the coil packs and they are right in the middle of the range. I insert the spark plug into the boot and ground the plug out and I get nothing when cranking on any of the coil packs. Could anyone clarify to me what the second wire is? I thought it was a ground but the plug is also grounded to the engine when threaded so I’m not sure. Appreciate any help.
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #3 ·
Not sure what wire you're talking about? What color is it?

Mark
So i looked into some wiring diagrams and found it is a ground, it’s the solid orange wire on one of the cylinders but the ground is different on each one. I guess it’s an intermittent ground which cuts in and out causing the spark but is controlled by the CDI/igniter. I’m am not getting this ground signal from my CDI and I cannot figure out why. I just tried swapping in a new CDI with no luck. The Crank POS sensor tested good on the ohm test per manual. What other inputs should I be checking? I am going to try cylinder ID and Cam pos. next I guess.
 

·
Just Me.
Joined
·
630 Posts
Pictures help. I often find it difficult to diagnose problems over the internet. In person, most of the time, they are simply straight forward, but working on a breeze of information is sometimes difficult.
 
  • Like
Reactions: 1202067

·
Is there anybody out there?
Joined
·
4,378 Posts
Don't know how much you know about coils and sparks? The orange wire goes to your ECU from the primary coil and when a spark is needed, the ground is taken away and the coil collapses which causes a spark on the plug via the secondary coil. I'm no expert but with power on, I believe you should have a ground on all four primary coils(12 Volts across primary coils). If you're not getting a spark on all four plugs, I'd suspect your pickup coil(have you checked it?) or the secondary circuit on your main switch(key). I believe this provides ground to your primary coils. Unplug the main switch, turn on the key and measure the resistance between the blue/yellow and blue/black wires. Should be less than one Ohm. Turn the key off and on and measure again. Do this several times. When the switch goes bad, they can be intermittent.

Edit: The pickup coil signals the ECU to create a spark.

Mark
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #6 ·
Pictures help. I often find it difficult to diagnose problems over the internet. In person, most of the time, they are simply straight forward, but working on a breeze of information is sometimes difficult.
So I’m getting spark now on all 4 coils consistently, so I put everything back together and tried to start and it just cranks and cranks like before. So I double checked work again and it was good so I started looking into the fuel, I pulled the injectors and cleaned them and they are all working good. I have a new all balls racing fuel pump in the tank now and I’m wondering if maybe I’m not getting enough pressure. I turned the key with the line off the gas tank and fuel will spray out a few feet but if I cover it with my thumb I can stop any from coming out no problem. So I’m wondering if maybe it’s not building enough pressure? The injectors are getting power and they were working good. If I try to crank the bike and pull the throttle back it sounds like the bike Boggs down and is harder to crank.If I give it a quick spray of starter fluid it will ignite for a second. So surely it’s not getting fuel.
 

·
Just Me.
Joined
·
630 Posts
Why does half of me want to say 'if you bridge the battery with a wrench, you'll get a spark'.
On one shoulder, you have a devilish representation of you. On the other, you have an angelic version. I'm not sure which is on each shoulder, but the devilish one is constantly whispering in your ear telling you to say...

Ahhh. You get it.
 
1 - 9 of 9 Posts
Top