KDX200 tons of smoke at 1/2 to full throttle

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Jludema
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KDX200 tons of smoke at 1/2 to full throttle

Post by Jludema »

Hello,

I recently acquired a 2000 KDX200 and have been trying to dial it in. It was running rich when I got it, I installed a 42 primary jet which helped. It was running well at full throttle, not too much smoke. I took it to a sandy Michigan trail a couple weeks ago, and ever since, it has been blowing tons of smoke at 1/2 to full throttle. Like huge clouds behind me after I give it some throttle, it definitely doesn't seem right and is worse then before. I checked compression, it is around 135 psi. I checked the air cleaner, it is good to go. I checked the muffler, it is newly packed and unclogged. I replaced the jet block gasket. The float seems approximately correct, I did mess with it to no avail. I installed a 40 primary and 145 main to see what would happen, it still blows a ton of smoke. I will probably go back to the 42 and 150.

As far as I can tell, it isn't burning oil, but I maybe haven't ridden enough to see a difference in the oil level. Any ideas on what the issue is? Burning coolant or oil? Is it normal? It doesn't seem to accumulate anything while sitting, it smokes a normal amount on startup, the extreme smoking is only at 1/2+ throttle.

Current mods:
145 Main
42 Primary
R1174K Needle 3rd notch
FMF Pipe
FMF Turbinecore II Muffler
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SS109
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Re: KDX200 tons of smoke at 1/2 to full throttle

Post by SS109 »

What color is the smoke?
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bufftester
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Re: KDX200 tons of smoke at 1/2 to full throttle

Post by bufftester »

If it's not blue smoke, then you need to do a leakdown check. Even if it is blue you need to do a leakdown check if its billowing clouds. You won't notice the oil loss until you've ridden it for a bit. Coolant you would notice the loss, and smell it. My guess is crank seals
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Re: KDX200 tons of smoke at 1/2 to full throttle

Post by KDXGarage »

Gasoline brand and octane??

Two-stroke oil and ratio??

Spark plug brand and model?

Too much information is not enough. :-)
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Jludema
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Re: KDX200 tons of smoke at 1/2 to full throttle

Post by Jludema »

93 octane, not sure where from
Lucas semi synthetic 32:1, no idea what the last guy ran
NGK BR8ES

It appears to be white smoke. I fashioned a leakdown tester and it goes from 15-0 in about 3 minutes, not good from what I have read. It's hard to tell where the leak is coming from, any ideas on next diagnosis step?
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Re: KDX200 tons of smoke at 1/2 to full throttle

Post by bufftester »

Well, you don't want to put 15 psi in on a leak check, 5 psi is sufficient and should hold for at least 5 minutes. Likely a crank seal internally if you don't notice any leaking from the exhaust/carb areas. Next step is to open it up (split the cases)
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Re: KDX200 tons of smoke at 1/2 to full throttle

Post by SS109 »

White smoke? Open your radiator cap and do another leak down at 5psi and see if you can hear air come out of the radiator.
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Re: KDX200 tons of smoke at 1/2 to full throttle

Post by KDXGarage »

Try 6 psi, not 15!
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