2001 kdx200 keeps fouling plugs

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bws2
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2001 kdx200 keeps fouling plugs

Post by bws2 »

I had my carb. cleaned about 6 months ago and since then the bike fouls plugs.

In the year prior I'd never fouled a plug. While riding recently I fouled two plugs, one within 4 miles of the other.

Both times the plugs were black and very wet. Any ideas on what's causing this?

One thought is jetting, over oiled air filter, but another suggestion was checking the reeds.

I haven't taken the bike apart myself before, so I'm a little worried about getting in over my head and making it worse.

Thanks in advance for any suggestions.
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KDXohio
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Re: 2001 kdx200 keeps fouling plugs

Post by KDXohio »

float height could be off, reeds and air filter are quick easy ones to check
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Re: 2001 kdx200 keeps fouling plugs

Post by Jaguar »

the valve that is used to regulate the fuel level in the float bowl could be cracked at its tip and letting too much gas in
Performance CDI -- KDX motocross mods -- the SR KDX -- expansion chamber analysis---> http://www.dragonfly75.com/moto/
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2001 kdx200 keeps fouling plugs

Post by ohgood »

bws2 wrote:I had my carb. cleaned about 6 months ago and since then the bike fouls plugs.

In the year prior I'd never fouled a plug. While riding recently I fouled two plugs, one within 4 miles of the other.

Both times the plugs were black and very wet. Any ideas on what's causing this?

One thought is jetting, over oiled air filter, but another suggestion was checking the reeds.

I haven't taken the bike apart myself before, so I'm a little worried about getting in over my head and making it worse.

Thanks in advance for any suggestions.

what plug are you using? I had tons of br8eix foul instantly, then finally switched to br8es and it was much better.

new reeds make a huge difference
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Sgt.harper48
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2001 kdx200 keeps fouling plugs

Post by Sgt.harper48 »

what plug are you using? I had tons of br8eix foul instantly, then finally switched to br8es and it was much better.

new reeds make a huge difference[/quote]


I thought BR8EIX are the iridium plugs ??? I've always heard they are much harder to foul out compared to the OEM style BR8ES plug. Maybe I'm not understanding correctly or it could be a difference in your jetting to mine or something that would make the difference.
bws2
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2001 kdx200 keeps fouling plugs

Post by bws2 »

ohgood wrote:
what plug are you using? I had tons of br8eix foul instantly, then finally switched to br8es and it was much better.

new reeds make a huge difference
Thanks Ohgood. I've been using the br8es plugs.

Hope I can get this problem figured out, since I'm not trusting the bike right now.
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Re: 2001 kdx200 keeps fouling plugs

Post by bws2 »

KDXohio wrote:float height could be off, reeds and air filter are quick easy ones to check
Thank you, KDXohio. Sorry to be a knucklehead, but what steps are needed to check the reeds.
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2001 kdx200 keeps fouling plugs

Post by ohgood »

Sgt.harper48 wrote:what plug are you using? I had tons of br8eix foul instantly, then finally switched to br8es and it was much better.

new reeds make a huge difference

I thought BR8EIX are the iridium plugs ??? I've always heard they are much harder to foul out compared to the OEM style BR8ES plug. Maybe I'm not understanding correctly or it could be a difference in your jetting to mine or something that would make the difference.[/quote]

I ran the same br8eix for a year, then fouled a handful of them. switched to br8es, no more fouls, and its mocha brown.
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Re: 2001 kdx200 keeps fouling plugs

Post by Jaguar »

dum-dums, you can't foul a plug in a few miles even if it's a bit too cold a rating.
Iridium is the only type plug I will use.
Performance CDI -- KDX motocross mods -- the SR KDX -- expansion chamber analysis---> http://www.dragonfly75.com/moto/
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Re: 2001 kdx200 keeps fouling plugs

Post by ohgood »

Jaguar wrote:dum-dums, you can't foul a plug in a few miles even if it's a bit too cold a rating.
Iridium is the only type plug I will use.

Challenge accepted ! Well, it's a past challenge, I managed to foul several of the iridium plugs a while back. Currnetly the iridium plugs still come out sooty and black/oily, while the non iridium plugs come out biscuit perfect.

I can't find a reason for this on the inter-wisdom-net, but I"m happy to learn about it if you can teach me. :)
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Re: 2001 kdx200 keeps fouling plugs

Post by Jaguar »

let's back up a bit. What is your definition of "fouled"?
you wrote: "While riding recently I fouled two plugs, one within 4 miles of the other."
Did the bike stop running?
Performance CDI -- KDX motocross mods -- the SR KDX -- expansion chamber analysis---> http://www.dragonfly75.com/moto/
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Re: 2001 kdx200 keeps fouling plugs

Post by KDXohio »

bws2 wrote:
KDXohio wrote:float height could be off, reeds and air filter are quick easy ones to check
Thank you, KDXohio. Sorry to be a knucklehead, but what steps are needed to check the reeds.
Pull the carb and pull the 6 bolts out intake manifold and pull out the reed cage out. When you hold it up the the light there shouldnt be any gaps they should seal against the block
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Re: 2001 kdx200 keeps fouling plugs

Post by bws2 »

Jaguar wrote:let's back up a bit. What is your definition of "fouled"?
you wrote: "While riding recently I fouled two plugs, one within 4 miles of the other."
Did the bike stop running?
Yes. Both times it just died on the trail. I could feel it cutting out and I opened the throttle wide trying to keep it going, but it just quit.

I couldn't get it started. Decided to try changing the plug, which has worked in other 'no start' situations recently.

Noticed the plug was wet and and black. Rode it back in the direction of my truck. Did a couple of stops and restarts

along the way and it re-started fine. Rode along a logging road at nearly full throttle, then turned into a trail and it died shortly after

(only 4 miles since the last time). Changed the plug again (wet and black), and it started. Thankfully, I got it to the truck (just 1/2mile away).
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Re: 2001 kdx200 keeps fouling plugs

Post by bws2 »

KDXohio wrote:
bws2 wrote:
KDXohio wrote:float height could be off, reeds and air filter are quick easy ones to check
Thank you, KDXohio. Sorry to be a knucklehead, but what steps are needed to check the reeds.
Pull the carb and pull the 6 bolts out intake manifold and pull out the reed cage out. When you hold it up the the light there shouldnt be any gaps they should seal against the block
Thanks KDXohio.
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Re: 2001 kdx200 keeps fouling plugs

Post by Jaguar »

I think it's your CDI, high voltage coil, or stator coil that is at fault. It takes way longer to foul a plug than a few miles. Being black does not mean it's fouled.
I think you are losing spark but not due to the plug.
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Re: 2001 kdx200 keeps fouling plugs

Post by bws2 »

Jaguar wrote:I think it's your CDI, high voltage coil, or stator coil that is at fault. It takes way longer to foul a plug than a few miles. Being black does not mean it's fouled.
I think you are losing spark but not due to the plug.
Thanks Jaguar. Any suggestions on how I can test these to see if any of them are faulty?
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Re: 2001 kdx200 keeps fouling plugs

Post by ohgood »

Jaguar wrote:let's back up a bit. What is your definition of "fouled"?
you wrote: "While riding recently I fouled two plugs, one within 4 miles of the other."
Did the bike stop running?

I've seen this similarly (around 3-5 miles from starting at home) with the iridium plugs. The plug looked at though it was dipped in tar when i pulled it, instead of the usual 'just a little wet' appearance a plug may have. Swapped to non-iridium (br8es) and it was fine. I sent an email off to ngk and they basically said it was a mixture issue, and an isolated incident.

The odd part was i did run an iridium for almost a year without issue prior to that happening. Hot/cold, fast / slow, single track/ road, it didn't matter on that older plug, but all of the recent (2015) plugs I tried would foul very soon after installing them.

I'm NOT saying you're wrong, i know you know your stuff, but just stating what happened with my experiences. :)

Last weekend I ran one of the br8es plugs for around 150 miles on pavement, fire roads, and double track in varying temperatures from foggy morning to thunderstorms and 85f sun drenched, all in the same weekend. No issue other than the slight adjustments for humidity at the air screw.

:) i did carry 4 plugs with me though, cause you just never know what might happen :)
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2001 kdx200 keeps fouling plugs

Post by Sgt.harper48 »

Going to agree with ohgood on this one I put a br8eix in mine today and after about 15 minutes of riding it fouled. Put a br8es in and ran the rest of the day with no issues. Next iridium plug I run may just be a denso plug just to see if NGK's "isolated incedent" is more or less an admission of " we don't want to come out tell everyone that we manufactured a crap load of bad plugs that never should have passed QC and been placed on store shelves." :naughty:
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Re: 2001 kdx200 keeps fouling plugs

Post by KDXohio »

I only ever fouled 1 plug in my dx it was after putting on the pipes and reeds and before i jetted it. Fouled as soon as the bike started but the bike was super rich.
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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2001 kdx200 keeps fouling plugs

Post by ohgood »

Sgt.harper48 wrote:Going to agree with ohgood on this one I put a br8eix in mine today and after about 15 minutes of riding it fouled. Put a br8es in and ran the rest of the day with no issues. Next iridium plug I run may just be a denso plug just to see if NGK's "isolated incedent" is more or less an admission of " we don't want to come out tell everyone that we manufactured a crap load of bad plugs that never should have passed QC and been placed on store shelves." :naughty:
man I really hope we're both overlooking something, or just wrong somehow.

the first plug was iridium, and lasted so long without issue. the previous owner said he never even looked at it in the three or four years he owned it, want sure it would come out so he never tried.

I don't have another br8eix to test the theory right now, but next time I have one I will and report back.

jaguar- i would really appreciate your opinion on this... I know you have a handle on stuff most of us will never grasp. :)
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