Erratic idling bike!

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Drussell
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Erratic idling bike!

Post by Drussell »

So I finally found time to finish up my bike. Put headlights, tails lights, rewound the lighting stator, replaced the front tube, new plastics, new pilot jet (same size), buffed pipe, etc..

I'm pretty happy with the bike until today.. I have been riding around the house. My brother had rode it hard for a little while about a week ago, everything was great and I was happy with the power. Then I get brave with it and instead of circling the block, I decide to head for the mountains.

I ride a mile out and it just dies... sounded like it ran out of gas. Had plenty of gas! When turning over it sounded like it was starting but immediately flattening out and dieing. Fouled sparkplug? Nope. After a few mins it starts back up like nothing happened but I was letting it idle while leaning on the kick stand. It revved out to the moon and the kill switch wouldn't stop it! I killed the gas supply and let it die out. So I start pushing. Decided to kick it over a few times at the top of a hill and it starts up and rides for an 1/8th mile and dies again. Repeat that but with out the revving to the moon part a few times and I make it back to the house.

96 kdx 200 with KnN air filter, fmf woods pipe, fmf turbine core 2, new reeds.

I noticed fresh gas sitting on too of the case, above the flywheel cover, below the cover that says KIPS. I wiped it off and tried cranking it back up. Gas was right back there. Appeared to be coming from the KIPS cover. Re sealed cover and now when I crank it i can't lean the bike towards the fly wheel side. It starts revving really high! I tried leaning the other way but it doesn't do anything... Help? I have no clue at this point..
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kawagumby
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Re: Erratic idling bike!

Post by kawagumby »

Likely the crank seal is shot on clutch side. When you lean it to the left the oil drops and more air gets in. I'd clean the carb too and put a filter in the fuel line.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
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SS109
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Erratic idling bike!

Post by SS109 »

And get rid of that K&N filter! They will do more harm than good on a dirt bike! TwinAir, Uni, No Toil, etc. are all better than the K&N.
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Drussell
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Erratic idling bike!

Post by Drussell »

So I should do a leak down test? I hope it's not a leaky crank seal.. last thing I need is to have to split the case
Drussell
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Erratic idling bike!

Post by Drussell »

Gonna have some time today or tomorrow to work on it. I was thinking about it, leaning the bike to the left (away from the clutch side) would cause the oil to completely cover the crankshaft seal wouldn't it? I haven't noticed a drop in oil or burning any oil?? I want to assemble a leakdown tester today or tomorrow. Does anyone know off hand the right size rubber plug things to buy for the intake and exhaust? Also, should I assemble a gauge to go in to the spark plug with a fitting to plug in a little hand pump? If the bike is having case leaking issues.. anyone have a case splitter they wanna sell?? One thing I should note too, is I am missing the clamp that goes on the carb boot. Was gonna order one but wanted to wait and see if it has leaking issues so I can make a big order at once if needed.
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kawagumby
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Re: Erratic idling bike!

Post by kawagumby »

yeah, you're right - the bike leaned to the left should increase the oil at the seal...and you should be able to smell it at the exhaust.
The only other thing I can think of that might cause the revs to increase with leaning the bike over is carb fuel level or something blocking fuel flow - even the gas cap vent could be a culprit - might explain why it runs for a while then goes lean (if the carb fuel level drops from a plugged vent line, that might explain the rise in rpm when you lean the bike over). Doesn't sound like a case leak based on what you've said.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
kenpowell
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Erratic idling bike!

Post by kenpowell »

SS109 wrote:And get rid of that K&N filter! They will do more harm than good on a dirt bike! TwinAir, Uni, No Toil, etc. are all better than the K&N.
What's wrong with the K&N? Do you have tests to back up your claims?
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Erratic idling bike!

Post by IDRIDR »

kenpowell wrote:
SS109 wrote:And get rid of that K&N filter! They will do more harm than good on a dirt bike! TwinAir, Uni, No Toil, etc. are all better than the K&N.
What's wrong with the K&N? Do you have tests to back up your claims?
It's a very touchy subject....kind of like which oil is best...

http://www.thumpertalk.com/topic/937672-kn-air-filters/
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