Spark plug fouling

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Redraider172
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Spark plug fouling

Post by Redraider172 »

Dear KDXrider.net users,

I have had my '03 KDX 200 for about 2 monthes now and i've had a problem occur twice. I'll be riding around my yard and the bike will make a sound like it just drowned itself and it then shuts off. I kick it many times and it won't start. I determined the problem to be a spark plug fouling so i cleaned it and it ran fine. The problem happened again yesterday and this time a good spark plug cleaning did not solve the problem. I run a 40:1 Fuel:oil ratio and that seems to be a bit thick based off the density of the exhaust but i am nervous about changing it because thats what the service manual reccomends. I've read several recomendations online about similar problems and some solutions were to adjust the jet and change my ratio. I was considering these options but i would greatly appreciate some more recomendations or solutions.

Nate
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rbates9
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Spark plug fouling

Post by rbates9 »

Like he said.

Also, when you foul a plug put in a new plug. Cleaning plugs is to get back home. Plugs are cheap and dirt bikes don't push easy. :wink:
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Re: Spark plug fouling

Post by Roadhazardguy »

If it still does it after you jet it down some it could be your right crank seal leaking transmission fluid into the crank case. Have you noticed your oil level going down?
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Re: Spark plug fouling

Post by KarlP »

Some jetting work is probably going to have to be done. It is not hard to do.

I've never had very good luck cleaning plugs. Once they foul they are pretty much done for.

I think 40:1 is fine. Just poking around in the yard with possibly rich jetting is bound to foul a plug.
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Re: Spark plug fouling

Post by Fletch »

could be time for a top end refresh too. That did it for me, and I haven't changed a plug since (about 40-50hrs ago)
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rbates9
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Spark plug fouling

Post by rbates9 »

Some cheap 2 stroke oils will also be more likely to foul plugs.
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scheckaet
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Spark plug fouling

Post by scheckaet »

or mixing different brand
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Re: Spark plug fouling

Post by teamgreen »

Check you reeds
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fuzzy
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Re: Spark plug fouling

Post by fuzzy »

and your air filter
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Redraider172
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Re: Spark plug fouling

Post by Redraider172 »

Thank you all for your responses. I use Yamalube oil for the mixture and thats legit from what i've read. Am i wrong? I just put in a new air filter before the problem happened the 2nd time and i checked it and it was fine. My oil level has been constant and i haven't noticed it going down. I don't know how to adjust the jets. Anyone got an article or youtube video link? Thank you all again for your help.
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rbates9
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Spark plug fouling

Post by rbates9 »

As far as which jets to use you will need to find out for your self by going thru this http://www.kdxrider.net/forums/viewtopi ... 105&t=1156 then you should be close.

If you are looking for a how to on getting at the jets then we can probably help you out there also.
Redraider172
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Re: Spark plug fouling

Post by Redraider172 »

Thanks a ton everyone, got it workin again :)
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rbates9
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Re: Spark plug fouling

Post by rbates9 »

Redraider172 wrote:Thanks a ton everyone, got it workin again :)
What did you do to fix it?
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fuzzy
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Re: Spark plug fouling

Post by fuzzy »

If you just put a plug in it will foul again. You've covered all the bases but jetting.
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Redraider172
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Spark plug fouling

Post by Redraider172 »

I put a new spark plug in and changed my mixture to 50:1 to avoid the problem again. If it happens again i'll adjust the jets. I realized i'd been cruising too much around the yard (despite its a 3x4 acre yard) I've noticed a larger than normal amount of oil coming out of the exhaust pipe. I feel like i need to ride it harder and keep in a lower gear for cruising.
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rbates9
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Spark plug fouling

Post by rbates9 »

Adjusting the oil mix to the bike isn't a great idea. It would be well worth your time to go thru the jetting and get that right. You will be surprised at the difference a well jetted carb will have on the overall performance of the bike.
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scheckaet
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Spark plug fouling

Post by scheckaet »

going from 1:40 to 1:50 ratio you've only done 1 thing and that is RICHEN your mixture.
you will foul plugs again.
rbates9 wrote:Adjusting the oil mix to the bike isn't a great idea. It would be well worth your time to go thru the jetting and get that right. You will be surprised at the difference a well jetted carb will have on the overall performance of the bike.
i get the feeling this will fall into death hears...some people refuse to listen no matter what :roll:
i think i'm done trying to help newb crying for help that won't listen to advice :butthead:
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Re: Spark plug fouling

Post by Steve_K »

yep.
Redraider172
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Re: Spark plug fouling

Post by Redraider172 »

okay' i'll change the ratio back and adjust the jets. I apologize for my ignorance. I have not been working on dirtbikes for very long so i am a little nervous about making mechanical adjustments as i have never really done it before.
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