No Spark

[jeffsfj1200]

Hey i would appreciate your help! I drove my bike it ran fine and then it sat a few hours started ran on like two cylinders then tried to give it gas to clear it out and it jus died! it has no spark! it will spark once on the first revolution of the bike then nothing! I think the coils might be bad any ideas on what it could b and on some aftermarket coils!

  Thanks  jeff

[MyFirstNameIsPaul]

If it's two cylinders failing at the same time, perhaps for some reason one of your coils is not firing.  Possibly either a power connector to the a coil, a bad coil, or something wrong with the ignition.

[SlowOldGuy]

Look for the easy stuff first!

Ignitions basically interrupt the 12V return line from the coil to make it fire (this would be on the "gorund" side of the coil).  Check for constant 12V to each coil.  Unhook and Ohm the coils and see if they are close to spec (which I have no idea what it is supposed to be, maybe 3 ohms?).

Inspect/clean EVERY electrical connector you can get your hands on. 

DavidR.

[jeffsfj1200]

The coils seem to be ok ithink its the ignition box! if i keep taping the starter button the bike throws spark and if i tun it over it sparks some times! if its the ignition box i think im going to get the dyna 2000 ignition! does rpm sell that to?

   thanks jeff

[MyFirstNameIsPaul]

Have you performed continuity checks on the wiring?  It would suck to replace the ignition and still have the same problem.  Solid-state ignitions rarely fail.

[jeffsfj1200]

No i havent done that eletrical is not my strong point! I think I might bring it to my buddies motorcycle shop! I really think its the ignitor box all the connections r clean and theres no bad wires i searched all over!

      Thanks   Jeff

[jeffsfj1200]

Well i was just screwing around moving around wires and the bike has spark again! started the bike up ran on to cylinders and then i looked at the tach and it didnt work then the bike woke up and then all the cylinders and the tach came back on! This bike is like christine! So my guess is tjeres a bad wire around somwhere i guess i stll dont know why the tach stopped working! Any suggestions to this!! Well like you guys said check the wiring Thanks again!

        jeff

[racerman_27410]

the tach reads off the coils.... and there is a ground wire right at the coils.... i would be checking that ground connection real close....


KOokaloo!


Frank

[RichBaker]

The tach gets its signal from one of the coils, I don't recall which one, but a look at the wiring diagram will show that....there's one at the yahoo site. Since the tach doesn't work when the cyls are dead, it'll be the same wire causing the problem. If you wiggle the wires at the coils, that may reveal which one is the problem...

Good luck, I've gotta get ready for work.

[jeffsfj1200]

Thanks rich and frank! i will take a look at the grounds this weekend!

    thanks jeff

[Dan Filetti]

Seems to me, we're all overlooking the fact that the FJ will start and run, albeit rough, on two cylinders. 

That's a thing.  It not every machine that "tries" that hard...

Dan

[rktmanfj]

Seems to me, we're all overlooking the fact that the FJ will start and run, albeit rough, on two cylinders. 

That's a thing.  It not every machine that "tries" that hard...

Dan

Maybe it's just a Yamaha thing.

My XS750 would run on one lung when the CDI went intermittent.     

Randy T
Indy

[andyb]

My XS400 does a similar trick.  Makes things interesting at times....

[rktmanfj]

My XS400 does a similar trick.  Makes things interesting at times....

Luckily, mine was under warranty at the time.

The dealer finally replaced it after 3 months (July/Aug/Sept) and a call to Yamaha corporate.   

Randy T
Indy