yz 250 fouling plug


25 replies to this topic
  • timpearson26

Posted January 20, 2008 - 10:34 PM

#1

I have a 97' YZ 250. I have owned it for about a year and it runs good all the time. Last Saturday though I ran out of gas on a trail. I was able to get back to my truck on another bike but I didn't have any premixed gas. I however got some regular 91 gas and filled up a gatorade bottle 3/4's full. I then got some 2t oil from the ranger that they use for their weed wackers. I just "eyeball" mixed it to what I thought looked good. I then put it in my bike and was able to get back to my truck (about a 3 minute ride back to the truck). The bike then sat at my house for 1 week.

Now 1 week later, I filled up the tank to the top with fresh gas. (I did not drain the gas that was left in the tank) The bike started up fine but it fouled the plug within minutes. I took out the plug, cleaned it, put it back. It then would start fine put would die and foul the plug again within about a minute.

My question: Should I just drain the gas and be good to go?
and/or
Did that crap gas that I left in the bike for 1 week gum up the carb/jets, and should I take out the carb and clean it?

  • yathump

Posted January 21, 2008 - 02:18 AM

#2

Drain all the old gas out(tank and carb)and put a brand new sparkplug in it

  • timpearson26

Posted January 21, 2008 - 10:23 AM

#3

after you foul a spark plug, can you reuse it if you clean it w/ carb cleaner and a wire brush, or if you foul it is it done?

  • RCannon

Posted January 21, 2008 - 12:45 PM

#4

They never are the same after they foul....even once. Something changes and its easy to have them mess up again.

  • USED YZ426F

Posted January 21, 2008 - 12:51 PM

#5

Just change out all the gas (tank and carb) and you should be good to go. I can't see how the mizing experiment would gum up the carb at all. You should replace the plug while you are at it.

  • BriAnJG054

Posted January 21, 2008 - 01:09 PM

#6

just replace the plug and you are fine. I agree with what rcannon says. you foul that plug once and for some reason they dont want to come back to life.

  • RCannon

Posted January 21, 2008 - 01:14 PM

#7

Brian, wonder why that is? You sound like you've tried it.

I always wanted to bring my eg's back to life because of the cost, but never succeeded.

  • OLDMAN62

Posted January 21, 2008 - 02:18 PM

#8

Brian, wonder why that is? You sound like you've tried it.

I always wanted to bring my eg's back to life because of the cost, but never succeeded.

My theory, (someone fee free to correct me) on fouled plugs is the "Fouling" is actualy a path of carbon which connects one electrode to the other and therefore shorts the plug out eliminating the spark. By cleaning with a wire brush, emory cloth, whatever you only succesfully remove a small portion of the carbon path and it will foul again quickly. This is just a guess

  • timpearson26

Posted January 21, 2008 - 02:55 PM

#9

Thanks you guys, I'll get a new plug and drain the gas. How easy is it to drain the gas out of the carb, do you have to take it off the bike?

  • yathump

Posted January 21, 2008 - 03:24 PM

#10

17 mm wrench to take the plug out of the bottom of the bowl

  • BriAnJG054

Posted January 21, 2008 - 04:18 PM

#11

My theory, (someone fee free to correct me) on fouled plugs is the "Fouling" is actualy a path of carbon which connects one electrode to the other and therefore shorts the plug out eliminating the spark. By cleaning with a wire brush, emory cloth, whatever you only succesfully remove a small portion of the carbon path and it will foul again quickly. This is just a guess


that would be my best guess. break cleaner, a wire brush, and an air hose still does not do the trick apparently. the bike will run for about 2-3 minutes and the plug will shit the bed again. I have had this problem plenty of times with a snowmobile but not so much with my yz. the yz is pretty good on plugs. :cool:

  • timpearson26

Posted January 21, 2008 - 05:02 PM

#12

17 mm wrench to take the plug out of the bottom of the bowl


saaaweeeeet!

  • Drtbikerider250

Posted January 21, 2008 - 05:08 PM

#13

Brian, wonder why that is? You sound like you've tried it.

I always wanted to bring my eg's back to life because of the cost, but never succeeded.


Where are you getting your plugs? I get the eg's for fairly cheap by buying them 4 at a time at the auto parts store instead of a bike shop. I can get the same plug that the bike shop sells for less than half the price.

I get 4 br8eg's for $15 at o'reilly's or advanced autoparts. the bike shop charges $8-10 each. Now that i've gotten both of my bikes running good though, i've had 6 or 7 spares sitting around for the last 6-8 months.

  • timpearson26

Posted January 23, 2008 - 05:31 PM

#14

Thanks guys. I drained the gas today out of the carb and tank, and threw in a new spark plug and some fresh gas. It fired up normal and didn't foul the plug.

BTW, I got 4 plugs at Roadrider (the local motorcycle shop) for $4.50 each.

Tim

  • Denn10

Posted January 24, 2008 - 01:49 PM

#15

Where are you getting your plugs? I get the eg's for fairly cheap by buying them 4 at a time at the auto parts store instead of a bike shop. I can get the same plug that the bike shop sells for less than half the price.

I get 4 br8eg's for $15 at o'reilly's or advanced autoparts. the bike shop charges $8-10 each. Now that i've gotten both of my bikes running good though, i've had 6 or 7 spares sitting around for the last 6-8 months.


WHAT $4 each for eg??? glad i snagged a box of 10 ev's from work. Didnt know they were that expensive these days.

  • BriAnJG054

Posted January 24, 2008 - 02:18 PM

#16

why not run an es ? is the eg any better ?

  • Agitator

Posted January 24, 2008 - 09:21 PM

#17

I'm glad you got it worked-out, man. :cool:

~Tator

  • MOTOXTREME222

Posted January 25, 2008 - 09:30 AM

#18

They make a sandblaster type machine that you can get to clean your plugs. Using a wire brush or other metal cleaning tools leave metal particals behind and that causes them to short out. Using the sandblaster works pretty good ive hardly had any problems re-using the plugs that have fouled before. Something to look into if your having big problems. Also can check your plugs with a volt meter for continuity to see it is ruined or not.

  • 2strokeYardSale

Posted January 25, 2008 - 03:23 PM

#19

I've got a $20 Harbor Freight spark plug cleaner. It's basically a media blaster and works great.

$4 plugs, ha! I use two $25 plugs on my TZ250. Newer TZ250s use $45 plugs.

  • MOTOXTREME222

Posted January 25, 2008 - 04:01 PM

#20

Champion also used to make a machine my buddy has one. It actually puts your sparkplug under compression like it would be in the engine. Has a glass viewing area so you can see the spark. Then it puffs air on it and if the spark goes out the plug is bad. Believe it or not some plugs spark outside of the engine and when you put compression to it they dont. Some of the newer car plugs actually have electronic chips in them that go bad too. New technology new problems!





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