04 WR450F electric start won't work

[Josh Ouse]

I need some help figuring out what is going on with my bike.  I have an 04 WR450F, and I was riding 5 miles of hell over the weekend.  Right before the last escape route (lucky me) my bike just died.  I was starting up a climb, and right at the base, it just shut down.  I didn't hit anything, don't even think there was much of a bump or anything to jolt the bike.  I did have a few lay downs/get offs before, but nothing here.  The light on the power button wouldn't turn on, and there was no power to the headlight.  I found out that I could kick start it, but it was very difficult, it took a LOT of kicking before it would start, and then it would stall if I ever let off the gas.  As I was trying to figure out what was going on, I saw some white plastic (?) pieces falling out from under the headlight/front number plate.  I pulled off the headlight and saw an electrical part (I assume it's like a resistor or something like that), it looked like it had been jarred loose, and got pinched by the steering, and broke it.  It is a white rectangular piece, looks and feels sort of like hard plastic, about 2" long, 3/4" wide and probably only about 1/4" thick, and has 2 male quick connectors on it.  Inside (since it broke, I could see, usually you wouldn't, but maybe it will help figure out what it is), is a thin wire coil, like a spring, and I'm not sure what it is wrapped around, maybe just an insulator.  I tried to wrap it with some electrical tape to insulate it while riding back, but it melted the tape, and was smoking.  

I'm not sure where the 2 wires that connect to it go, they go back into a cluster of wires on the wiring harness, and I didn't have time to cut it all apart, and follow them, but that is the only damage that I could see, so I'm hoping that if I can figure out what this part is, and find a replacement, that will fix my problem. 

Any help or advice is greatly appreciated.

Thanks,

[jimmym]

Take a look at the electrical diagram, does the piece look familiar to anything here: https://www.partzilla.com/catalog/yamaha/motorcycle/2004/wr450f-wr450fs/electrical-1 

[Josh Ouse]

Jimmym, yes, I've looked at that diagram several different times, and from a few different websites hoping it would be different, but they are all the same, and I don't see it on there.  I believe the 2 wires that plug into the part get tucked into the wiring harness, and then go... I don't know where

 

[Qball1982]

I know very little about WR’s having just took delivery of my first one. The only thing iv seen on mine that sounds similar to what you described is the TIP sensor but mine is underneath the battery. 

[S.O.A.N.Z]

can you take some pics so we know what we're looking for

[Josh Ouse]

ya, here are some pics of the part, not sure how much they will help, because the white ceramic (?) that surrounded it is pretty much all gone, 1 piece was still there, but it fell off while taking pics, but originally I said it was plastic, now I'm pretty sure it is more like ceramic (sort of a sandy/gritty feel to it).  The first pic is hard to see, but the part is down towards the bottom, this is under the headlight/number plate, right above the front fender.  2nd pic is a closer shot of it still hooked up.  3rd pic, I took it off the bike for a close up.  So it looks like a fiberglass rod with wire wound around it, and it was all encased in the ceramic (I think) that you see on the left of pic 3, and then 2 wires were attached to it, 1 on either side.  The 4th pic is kinda blurry, but shows it hooked up to the wires, and the last piece of ceramic sitting there too.

[S.O.A.N.Z]

studies a few diagrams and all i can come up with is a starting circuit relay

[raYzerman]

That looks like a resistor like we used to have on old cars ignition (resistor for the coil), or the one that comes with heated grip kits....... yes ceramic and they get hot....  thing is, I've never heard of one on a bike in the ignition circuit but don't know much about '04 WR's either.  Are you sure it's original or is there some aftermarket ignition system?

BTW, at one time you could buy this at RadioShack, but I'll bet you can get it at an automotive supply...

 

[foggy3061]

11 hours ago, Josh Ouse said:

ya, here are some pics of the part, not sure how much they will help, because the white ceramic (?) that surrounded it is pretty much all gone, 1 piece was still there, but it fell off while taking pics, but originally I said it was plastic, now I'm pretty sure it is more like ceramic (sort of a sandy/gritty feel to it).  The first pic is hard to see, but the part is down towards the bottom, this is under the headlight/number plate, right above the front fender.  2nd pic is a closer shot of it still hooked up.  3rd pic, I took it off the bike for a close up.  So it looks like a fiberglass rod with wire wound around it, and it was all encased in the ceramic (I think) that you see on the left of pic 3, and then 2 wires were attached to it, 1 on either side.  The 4th pic is kinda blurry, but shows it hooked up to the wires, and the last piece of ceramic sitting there too.

Whatever it was, it looks to have been plugged into the original headlight wiring?

[Josh Ouse]

rayezerman, yes, that looks very close to what it was, but I'm not sure if it is original or not, I think I'm the 3rd owner, so I'm not sure what has been done to it before me, and this is my first WR.

Foggy, I'm not sure what the wires go to, haven't cut into the harness to follow the wires, but I assumed that it had the original headlight still, it doesn't look aftermarket to me.

My next question, then, would this make it so my starter would work, and make it hard to kick start, and run really rough after kick starting it?  Or do I have another problem somewhere also?

 

Thanks for all the help and advice!!

[raYzerman]

It may do all of that, if it's broken and intermittent.  That circuit may require a complete connection to enable the starter.  Will it cause rough running, I'd think so.  If it was intermittent while you were kick starting, that ignition circuit may be open while you're kicking/vibration.

The easy fix is go get one, they're cheap.  Meanwhile, I'd think of how one could eliminate it, but that would require detective work to see why it's there and what circuit it's in, etc.

[foggy3061]

1 hour ago, Josh Ouse said:

Foggy, I'm not sure what the wires go to, haven't cut into the harness to follow the wires, but I assumed that it had the original headlight still, it doesn't look aftermarket to me.

It might well be the original headlight unit on the bike but the wiring you have there is the original headlight connection but removed from the black 3 pin bulb connector. Thats why the terminals are the right angle 'Flag' type.

Originally the yellow is the headlight supply and the piggy backed blue wire is the supply to the rear light.

[raYzerman]

With Foggy's info...... I'm now thinking the headlight had to be part of the starting/run circuit somehow and provide a resistance value if the headlight has been removed.....

[Josh Ouse]

OK, for the cheap fix, do I need to get a specific one, ie. are there different specs, do I need to find out exactly which one is on it now, or are they relatively similar, and any one will work?

On a side note, I talked with a local dealer parts dept, and they said that the 04 WR's shouldn't have a ballast resistor, so... in the long run, I'm not sure what the next step should be...

[raYzerman]

The ones I have seen for heated grips for example are 27W and 10 amps, but any standard ignition ballast resistor will be about that..... no worries about being too specific, it will be close enough IMHO.

[Josh Ouse]

thanks for the info guys, I ordered the cheapest one from Autozone that looks similar to what I had, will pick it up tomorrow, and hope that works, I'll let you know.  ?

 

[Red800rider]

I'm an electronic tech, that IS a high wattage resistor, but it could be any resistance from .1 ohm to 1M ohm. In layman's terms 10,000,000 times difference in value....... you are rolling the dice with random value. Find out where it goes and/or schematic

[DeepPurplishBlue]

It is definitely a high watt resistor, and looks like it is plugged into the stock headlight connection.

Most likely someone removed the stock headlight and put that in it's place.     As Red800 said you have no idea now what value it is because of the damage, but you don't have to be spot-on with it.   Stock H4 bulb is about 50 watts, which at 12 volts would be 4 amps.    Ohm's law tells us a 4ohm resistor would put you at 3 amps, 36 watts.  Close enough.    You could go 3ohms and get closer to 50 watts but it is pointless...  just makes the stator work harder for no reason and the resistor runs hotter.   But having said all of that these bikes will run fine without the headlight circuit being loaded down all the time.  Yamaha sold these bikes with headlight switches for a number of years.

You mention you have a headlight that stopped working when the problem began...  you have an aftermarket light?    If so is it connected directly to the battery?   You might want to rethink the wiring on this bike and connect the headlight to the stock headlight connector.  

 

[Josh Ouse]

I'm not sure if the headlight is aftermarket or not, I thought it was stock, but it could be that it was switched out when the previous owner added the street legal kit to it.  And it wasnt' just the light that went out, the ignition/power button went out, along with the electric start.  When I was kicking it, sometimes the power light on the ignition button would light up, and that is when it sounded like the kicking was actually going to get the bike started, so I don't know if that is because all the jerking from kicking the bike made a temporary connection somewhere, or....

 

The resistor that I got, that looks close to the other one (I know that doesn't mean much, but it's all I had to go off of) is a resistance of 1.4 ohms... is this likely to be too small, and cause me problems?

[DeepPurplishBlue]

If the battery goes down you will see symptoms like you describe with the red LED.   If you use the kick starter the stator usually makes enough power to start the bike.   That is why you see the red LED come on when kicking.

Post up a picture of the headlight and how it connects to the bike...

1.4 ohms is way too small..  that works out to over 100 watts at 12 volts, which is far more than the lighting coil on the stator can deliver.