Sticky Powervalve

Discussion specific to the 1995 - 2006 KDX200 (H Series) and 1995 - 2005 KDX220R (A Series) models sold in the USA
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bergilong
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Sticky Powervalve

Post by bergilong »

I have an issue with my powervalve sticking when the engine is cold. It's like you have to force it open, but it will work fine after that.
I fully disassembled the powervalve and cleaned it. I lubricated it with two stroke oil and put it back together. The issue is still there. What could be causing it?

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Chilly
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Re: Sticky Powervalve

Post by Chilly »

Just when it’s cold?
ohgood
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Sticky Powervalve

Post by ohgood »

bergilong wrote:I have an issue with my powervalve sticking when the engine is cold. It's like you have to force it open, but it will work fine after that.
I fully disassembled the powervalve and cleaned it. I lubricated it with two stroke oil and put it back together. The issue is still there. What could be causing it?

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You pulled the sub valves, cleaned all the carbon off and lubricated everything again?
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Re: Sticky Powervalve

Post by John_S »

If the KIPS is all assembled (cylinder off the bike) and you remove the spring and ball detent that's under the left side slotted screw you should be able to spin the right side gear with your fingers all the way through open and closed with no resistance at all. Once the spring and ball are in place it takes some effort to get it started with your fingers and then it turns freely. Do you have both brass washers in place on the spring and ball bolt?

If it's back on the bike try to remove the spring and ball and the left hand thread nut and turn the gear manually. I wonder if the oring on the right side kips shaft is swollen from brake cleaner or other solvent. That seems like it would be hard to operate cold and then slide better when the cylinder is warm.
bergilong
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Re: Sticky Powervalve

Post by bergilong »

John_S wrote:If the KIPS is all assembled (cylinder off the bike) and you remove the spring and ball detent that's under the left side slotted screw you should be able to spin the right side gear with your fingers all the way through open and closed with no resistance at all. Once the spring and ball are in place it takes some effort to get it started with your fingers and then it turns freely. Do you have both brass washers in place on the spring and ball bolt?

If it's back on the bike try to remove the spring and ball and the left hand thread nut and turn the gear manually. I wonder if the oring on the right side kips shaft is swollen from brake cleaner or other solvent. That seems like it would be hard to operate cold and then slide better when the cylinder is warm.
The bolt has both washers. Sorry for taking so long to reply

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bergilong
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Re: Sticky Powervalve

Post by bergilong »

ohgood wrote:
bergilong wrote:I have an issue with my powervalve sticking when the engine is cold. It's like you have to force it open, but it will work fine after that.
I fully disassembled the powervalve and cleaned it. I lubricated it with two stroke oil and put it back together. The issue is still there. What could be causing it?

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You pulled the sub valves, cleaned all the carbon off and lubricated everything again?
Yes

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bergilong
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Re: Sticky Powervalve

Post by bergilong »

Do you think the washers could be compressed and I just need new ones?

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John_S
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Re: Sticky Powervalve

Post by John_S »

Remove the spring and ball (careful not to lose the ball), put the bolt with washers back on and take it for a ride. That allows the KIPS valve to open easier. I removed them and won't be putting them back in. The power is still linear but it made a good difference in mid range throttle response.
bergilong
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Re: Sticky Powervalve

Post by bergilong »

John_S wrote:Remove the spring and ball (careful not to lose the ball), put the bolt with washers back on and take it for a ride. That allows the KIPS valve to open easier. I removed them and won't be putting them back in. The power is still linear but it made a good difference in mid range throttle response.
I'll give this a try tomorrow and let you know the results

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bergilong
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Re: Sticky Powervalve

Post by bergilong »

I removed the ball and spring. It didn't fix the problem

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Re: Sticky Powervalve

Post by KDXGarage »

Did you have the cylinder recently replated?
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Re: Sticky Powervalve

Post by bergilong »

Jason wrote:Did you have the cylinder recently replated?
Nope

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Re: Sticky Powervalve

Post by KDXGarage »

I once heard of a cylinder that had been plated. It had some plating inside the KIPS area causing it to bind.
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Re: Sticky Powervalve

Post by bufftester »

How are you checking it so that you know it doesn't work when cold but does when warm? Was a manual and a torque wrench used? Have you inspected the centrifugal actuator under the right hand engine cover? Good advice from JohnS about checking it off the bike before reassembly to verify operation.
bergilong
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Re: Sticky Powervalve

Post by bergilong »

bufftester wrote:How are you checking it so that you know it doesn't work when cold but does when warm? Was a manual and a torque wrench used? Have you inspected the centrifugal actuator under the right hand engine cover? Good advice from JohnS about checking it off the bike before reassembly to verify operation.
A manual and an inch-pound torque wrench was used. I'm thinking it might be the centrifugal actuator. How would I inspect it?

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bergilong
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Re: Sticky Powervalve

Post by bergilong »

I did check the powervalve actuation off the bike. It was buttery smooth and completely opened and closed.

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Re: Sticky Powervalve

Post by bufftester »

Easiest way is to pull off the round KIPS cover on the LH side and run the bike. Around 6k rpms you should see the shaft rotate when the valve opens. Possible the actuator arm is tweaked. To visually inspect you would have to pull the RH engine cover off (the bigger one, not the clutch only one). The build up is visible HERE. There is a bearing that the governor shaft rides in that could be bad, or something out of whack. But if it worked off the bike manually then I would probably focus on installation and torquing. In other words, basically take off the cylinder, verify it works. Put it on the motor and torque the head on, then check KIPS. Keep repeating as it is reassembled, every time you tighten something check KIPS action (obviously you don't want to install the pawl or the LHT nut while doing this) Perhaps that will help isolate where the problem starts. Good luck on this, it can be frustrating.
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