07 yz 450 stalled out today ???

[yamaha6j]

I hit a big table top jump that basicaly was like a step up jump in the x games and when I landed the bike acted like it ran out of fuel( was doing it all day no problems before). I knew that I could be low on fuel, however I filled her up and she still wouldn't start. What do I do now??

[grindrod89]

before anything you should make sure ur plug isnt fouled out.

[yamaha6j]

Four stroke fouled out plug ? I never thought to check it. I mean tomorrow we will be looking for the basics fuel, spark, air. But you think it might be something like that.

[FreshDonutsCAN]

its gotta be the plug and mixture. Mine did the same thing as it was fouling plugs!

[grayracer513]

How hard did you land? It has happened that the carb can separate from the isolator on a hard impact if it's loose.

[yamaha6j]

Ok, thanks for the help here but it was not the plug. I'm not getting any spark from what I can see. I put a new plug in and there is no spark? What can it be now?

[grayracer513]

Test the stator output. A few '07's have had stators fail.

[yamaha6j]

Thank's for the help. I was thinking the same thing. The question is how to test it??? What steps would you do?

[todds924]

Are you saying the bike stopped altogether and wouldnt re-start? I did a race this past weekend on my 08 and that very thing happened......I was leading at the time also....really pissed me off. I went through an uphill whoop section and when i got to the top the bike just died. I tried bumping it down the backside and it wouldnt lite. Took around 8 kicks and it finally started. Never happened again the rest of the day. Felt like it ran out of gas and there was plenty of fuel. It did this one time before when i first got it and i didnt think anything of it. The only thing i can come up with is the outside temps were around 100 degrees. I think its a little fat down low. I have since changed my jetting and will try it tomorrow.

[grayracer513]

Thank's for the help. I was thinking the same thing. The question is how to test it??? What steps would you do?

First, I'd disconnect the kill switch wire, just because it's simple, and test again for spark with a new plug.

The owner service manual doesn't cover the stator, but here's how I'd test it:

Find the 6 pin connector coming up from the stator (under the tank). With the connector unplugged from the harness, using a digital VOM on the stator side of the connector, make these checks:

> Connect the tester leads to the white and red leads. There should be continuity with some resistance. If this is OK, connect one test lead to either lead, and the other to ground. This should show an open circuit (no continuity.

> Connect the tester leads to the green and brown leads. There should be continuity with some resistance. If this is OK, connect one test lead to either lead, and the other to ground. This should show an open circuit.

> Connect the tester leads to the black and pink leads. There should be continuity with some resistance. If this is OK, connect one test lead to the pink lead, and the other to ground. This should show the same resistance as between black and pink. Now test between the black lead and the ground. This should show no resistance.

If it passes all these tests, and with the connector still unplugged, check the output. If you have an analog VOM, it may be more useful for this test. Set the meter to read AC volts.

> With the leads connected to red and white, you should get one small spike of voltage each revolution.

> With the leads connected to green and brown, and again to either pink and black or pink and ground, the meter should show voltage when the engine is cranked.

If it does all that, it should work.

But I have to say that not withstanding your statement that the bike has no spark, my first thought was like Todd's; a fuel problem related to heat.

[yamaha6j]

Todd, your story is like mine, except I was not in a race just practice. I'm going to try and test it the way Gray has said so here ( thank you Gray you should get paid ). I will let you know the outcome of that later on. I put a new plug in the cap and tried to see if I could get spark with no luck. Do you think that maybe I wasn't getting a good ground resting the plug on the motor? I also tried it on the stainless head pipe. Again there was no spark either way. So now it's testing the stator.

[todds924]

Todd, your story is like mine, except I was not in a race just practice. I'm going to try and test it the way Gray has said so here ( thank you Gray you should get paid ). I will let you know the outcome of that later on. I put a new plug in the cap and tried to see if I could get spark with no luck. Do you think that maybe I wasn't getting a good ground resting the plug on the motor? I also tried it on the stainless head pipe. Again there was no spark either way. So now it's testing the stator.

I rode today in 100 degree heat and the bike didnt miss a beat. I rode 4 - 20 minute practice motos. I did change up the jetting a little. I dropped the 45 pilot to a 42....changed the needle to an NFLP/5th groove. 2 turns on the mixture screw. I like it. Works good in the heat with the PC pipe. I was also thinking about the kill switch thing. I noticed when the bike was tied down in my truck, the kill switch wires were kinda pinched under the strap.

[yamaha6j]

Gray, thanks for the steps to walk me thru on the stator. It failed with the green and brown part so I ordered a new one. Its funny because that is one of the things they say the addresed with the 09 yz. I will give Yamaha props as it looks like the part # for it has ben updated. That makes me think they know about it and have hopefully addresed it with a newer one.

Thanks again,

Matt

[yamaha6j]

Gray, the stator was to blame all along !!! Thanks for help in making sure I didn't throw out a bunch of money for somehting that wasn't it.

[todds924]

My bike did it again today!!!!!!!!!!! I'm getting really pissed. My 06 never did this. I'm going back to square one. Stock jetting with my 08/ 06 stock pipe combo. Also completely going through the carb. Who knows? float level might be off. It was pretty hot out, but it ran fine for the first moto.

[yamaha6j]

Todd, let me know what the outcome is. I'm not sure what it could be, sounds pretty strange and not normal at all. Todd if you like replace the stator. It wasn't a big thing to do and cost around $ 140 with a plug ang gasket. Good Luck !