02 426 backfiring, stalling and making no power.


57 replies to this topic
  • etuke

Posted November 11, 2012 - 07:08 AM

#41

stator on my kx250 died on me this summer,I was driving and it started to pop then lost all power and died.Stopped took out the plug figguring it had fouled and everything looked ok,popped it back in and she fired right up and ran perfect for about another 100' then died all together,so stators can cause some weird problems when the windings start to short.

  • Jtt_R

Posted November 11, 2012 - 01:46 PM

#42

I'll have mine in early Tuesday so we shall see if the new stator fixes it.

  • AlexJohncock

Posted November 11, 2012 - 02:53 PM

#43

Jtt Please let us know how it goes!

  • Jtt_R

Posted November 11, 2012 - 04:09 PM

#44

So i got my new stator early; however, it's not on yet because i don't have the gasket. Nevertheless, I'm impatient so i pulled the old one off and found my culprit. I'll post pics in a bit but some of the sealer around the wires was coming off. Upon further inspection two wires were not attached/properly soldered into place any longer. If i can salvage the old gasket in one piece I'll get everything together and start it up.

  • Jtt_R

Posted November 11, 2012 - 05:35 PM

#45

Bike is no longer popping and shoothing flames on the acce and the miss is gone. So new stator fixed it; however, now I have the decel pop and when I checked the oil level just now (just did and oil change) I've got bubbles in the oil on the stick? Any ideas on that?

  • grayracer513

Posted November 11, 2012 - 06:38 PM

#46

Regarding the decel pop:

http://www.thumperta...599#post3710599

As to the dip stick thing, the bubbles are typical. Your bike is a dry sump system, even though on the '07 it looks like the oil is in the crankcase. There's an internal oil "tank" in the front section of the cases where the dipstick is, and there are two oil pumps. One pump feeds the engine and transmission, including the clutch, and the other one sucks up all the oil that drains back to the bottom and returns it to the tank.

Since the return pump moves oil at least twice as fast as the feed pump does, it is almost always slurping air, and that air gets pumped up the return passage to the tank. Never guess where it comes out; right onto the dip stick. That means that if you shut the bike off and don't wait at least a minute before checking, you'll usually see bubbles.

Read more:

http://www.thumperta...903#post5221903

  • Jtt_R

Posted November 11, 2012 - 07:33 PM

#47

Ok thanks, the bubbles had me worried. I stopped wrenching on the thing after i got the stator in so I'll fiddle with the decel popping tomorrow.

  • Jtt_R

Posted November 12, 2012 - 03:40 PM

#48

Posted Image

Posted Image

These are the wires coming off the stator up to the CDI box. They were hanging on by just a few strands of wire. Like I said the loud 12 guage popping and 3 foot flames are gone. Now I just have a little pop when I let off the throttle. I'll need to adjust the idle and then the fuel screw since I messed with them before fixing the stator issue.

  • AlexJohncock

Posted November 12, 2012 - 06:08 PM

#49

Awesome! I'm happy to hear you figured yours out.

I will pull mine off soon and inspect it. Did you use the special tools to get it off? And if not, how do you recommend going about it?

Thanks!

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  • Jtt_R

Posted November 12, 2012 - 07:33 PM

#50

I'm not sure how much the 03 will differ but mine was bolted to the cover. So you'll need to drain your oil, disconnect the wires, and pull the cover. Then the stator is bolted to the inside of the cover. Mine had T bit screws so you might need those. There are 3. The phillips head screws can be left alone. Then to reinstall you'll need a new gasket.

  • jojo1224

Posted November 12, 2012 - 10:21 PM

#51

I'm not sure how much the 03 will differ but mine was bolted to the cover. So you'll need to drain your oil, disconnect the wires, and pull the cover. Then the stator is bolted to the inside of the cover. Mine had T bit screws so you might need those. There are 3. The phillips head screws can be left alone. Then to reinstall you'll need a new gasket.


A 426 and 400 will have the stator bolted to the center cases not on the cover. You will need a flywheel puller (27mm X 1mm LH thread, alot of hondas use the same one btw) and sometimes an impact gun to remove the nut. No need to drain the oil if you shut off the gas and lay the bike over.

  • grayracer513

Posted November 13, 2012 - 12:01 PM

#52

A 426 and 400 will have the stator bolted to the center cases not on the cover. You will need a flywheel puller (27mm X 1mm LH thread, alot of hondas use the same one btw) and sometimes an impact gun to remove the nut. No need to drain the oil if you shut off the gas and lay the bike over.


Same is true of the '03-'05 YZ450

  • Jtt_R

Posted November 13, 2012 - 05:07 PM

#53

That sucks. Being bolted to the cover made it super easy. Hopefully it is easier then it sounds for you guys.

  • AlexJohncock

Posted November 13, 2012 - 07:05 PM

#54

Ha! I pulled off the cover on mine today to find out the the sensor that tells the ignition when to fire was loose! One of the stupid phillips head screws had fallen out and the other that was left was loose.

I got two new socket head cap screws for it and put them in, threw it back together and it runs great. I can't believe that's what was causing it the whole time. Literally a $1.00 and ten minute fix.

Now the only problem is that there is a screw floating around in the crank case somewhere. Not sure how I'm gonna find it. Any suggestions are welcome.

  • etuke

Posted November 14, 2012 - 03:54 AM

#55

while you had the cover off you should have used a magnet to fish around untill you found it.

  • grayracer513

Posted November 14, 2012 - 07:53 AM

#56

If the screw's not stuck on the magnets inside of your flywheel waiting to destroy your stator, maybe it will slide over to the other side and break the oil pump drive gear. That'd be one way of finding it.

OK, maybe not the best way. :excuseme:

  • AlexJohncock

Posted November 14, 2012 - 08:14 AM

#57

I did fish around with a magnet, and I intend to do more. I have a scope that I can borrow from work to take a look too, so I think I'll try that.



while you had the cover off you should have used a magnet to fish around untill you found it.



  • 72degrees

Posted November 14, 2012 - 11:11 AM

#58

I have a useful gadget that is a strong magnet on the end of a telescopic rod and incorporating an LED. So strong you can pick up a dropped spanner from the bottom of a car engine bay. About half an inch diameter though so not very useful inside an engine. Something tiny, very magnetic and flexibly mounted would be ideal. Something like a magnamole but capable of bending round tight corners http://e-magnetsuk.com/magnamole.aspx





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