Clutch slip!

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Strictly Kdx
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Clutch slip!

Post by Strictly Kdx »

So I’ve had my 99 Kdx 200 since day was 14, I’m 23 now and I’ve always had an issue with my clutch slipping and I’ve replaced the clutch about 4 times (after rebuilds and all). I put two heavy duty valve springs in there and it seemed to work fine for a while, but now after this last build I’ve added a platinum series pro circuit pipe and vforce 3 reed valves as well as a down sized idler jet for the carb and now it seem like it’s just too much power. Anyway I was wondering if anyone has a particular upgrade or mod to help this issue.
Bootom lone is something is wrong if I had to put stronger springs in it since I got the bike 10 years ago I also haven’t use friction modified oil in the bike either

Also I should state that I’ve thoroughly checked the explorer view of the clutch online and I have watched a few videos of other rebuilding the same clutch

One last thing is, I was looking at pictures from a maual online and happened to notice that there was 5 springs instead of 4, any explaination for this? Do I have the wrong clutch cage or basket in the bike? How can I find out
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Re: Clutch slip!

Post by SS109 »

Strictly Kdx wrote: 07:28 pm Jul 31 2019 So I’ve had my 99 Kdx 200 since day was 14, I’m 23 now and I’ve always had an issue with my clutch slipping and I’ve replaced the clutch about 4 times (after rebuilds and all). I put two heavy duty valve springs in there and it seemed to work fine for a while, but now after this last build I’ve added a platinum series pro circuit pipe and vforce 3 reed valves as well as a down sized idler jet for the carb and now it seem like it’s just too much power. Anyway I was wondering if anyone has a particular upgrade or mod to help this issue.
Bootom lone is something is wrong if I had to put stronger springs in it since I got the bike 10 years ago I also haven’t use friction modified oil in the bike either

Also I should state that I’ve thoroughly checked the explorer view of the clutch online and I have watched a few videos of other rebuilding the same clutch
Replace your springs with the correct OEM springs. Seriously, don't try to play around with this as you won't fix it and/or you'll create other problems. Next, have you measured your steels and frictions to make sure they are within spec? How grooved is your basket? What is your clutch lever free play set at? What spec oil have you been using specifically?

Strictly Kdx wrote: 07:28 pm Jul 31 2019One last thing is, I was looking at pictures from a maual online and happened to notice that there was 5 springs instead of 4, any explaination for this? Do I have the wrong clutch cage or basket in the bike? How can I find out
The pics in the '95+ manual were reused from the '89-'94 KDX manual which did use 5 clutch springs. The '95 and newer bikes use only 4 springs.
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Re: Clutch slip!

Post by bufftester »

Yes on the OEM springs. I have found that the springs in every EBC and Tusk kit I have bought were not within spec. As stated, check your notching, and your steel/friction plate wear prior to rebuild. Some guys have had good luck using ATF fluid over regular oil as well.
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Re: Clutch slip!

Post by Strictly Kdx »

SS109 wrote: 01:08 am Aug 01 2019
Strictly Kdx wrote: 07:28 pm Jul 31 2019 So I’ve had my 99 Kdx 200 since day was 14, I’m 23 now and I’ve always had an issue with my clutch slipping and I’ve replaced the clutch about 4 times (after rebuilds and all). I put two heavy duty valve springs in there and it seemed to work fine for a while, but now after this last build I’ve added a platinum series pro circuit pipe and vforce 3 reed valves as well as a down sized idler jet for the carb and now it seem like it’s just too much power. Anyway I was wondering if anyone has a particular upgrade or mod to help this issue.
Bootom lone is something is wrong if I had to put stronger springs in it since I got the bike 10 years ago I also haven’t use friction modified oil in the bike either

Also I should state that I’ve thoroughly checked the explorer view of the clutch online and I have watched a few videos of other rebuilding the same clutch
Replace your springs with the correct OEM springs. Seriously, don't try to play around with this as you won't fix it and/or you'll create other problems. Next, have you measured your steels and frictions to make sure they are within spec? How grooved is your basket? What is your clutch lever free play set at? What spec oil have you been using specifically?

Strictly Kdx wrote: 07:28 pm Jul 31 2019One last thing is, I was looking at pictures from a maual online and happened to notice that there was 5 springs instead of 4, any explaination for this? Do I have the wrong clutch cage or basket in the bike? How can I find out
The pics in the '95+ manual were reused from the '89-'94 KDX manual which did use 5 clutch springs. The '95 and newer bikes use only 4 springs.

So basically even after odering “upgraded” clutch springs it is likely the oem springs are bette? And I will have to check the friction plates other than that everything else is up to spec but there are some notches in the clutch basket I’ll post pictures tomorrow when I get to work on the bike, also the oil I’ve just started using has friction modifiers which is deffinetly not good but I’ve never used oil like this before anyway. The basket is indeed grooved or notched, I’ll post pictures tomorrow about it when I get to work
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Re: Clutch slip!

Post by Strictly Kdx »

bufftester wrote: 02:51 pm Aug 01 2019 Yes on the OEM springs. I have found that the springs in every EBC and Tusk kit I have bought were not within spec. As stated, check your notching, and your steel/friction plate wear prior to rebuild. Some guys have had good luck using ATF fluid over regular oil as well.
I’m gonna give the atf fluid a try and yea I guess I’m gonna have to check those spring specs and see what I get also I found that the notches in the clutch basket could be holding thing up so I’m gonna file them and if that fixes it I’ll be getting a new clutch basket
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Re: Clutch slip!

Post by kdxsully »

Strictly Kdx wrote: 09:38 pm Aug 01 2019
bufftester wrote: 02:51 pm Aug 01 2019 Yes on the OEM springs. I have found that the springs in every EBC and Tusk kit I have bought were not within spec. As stated, check your notching, and your steel/friction plate wear prior to rebuild. Some guys have had good luck using ATF fluid over regular oil as well.
I’m gonna give the atf fluid a try and yea I guess I’m gonna have to check those spring specs and see what I get also I found that the notches in the clutch basket could be holding thing up so I’m gonna file them and if that fixes it I’ll be getting a new clutch basket
I use the type F, if you didn’t know which atf we’re talking about
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Re: Clutch slip!

Post by Strictly Kdx »

Thanks I’ll try that first, but I was gonna just use my best assumption based off what I read online from others choices, seems like type f isn’t most common though
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Re: Clutch slip!

Post by kdxsully »

Strictly Kdx wrote: 07:31 pm Aug 02 2019 Thanks I’ll try that first, but I was gonna just use my best assumption based off what I read online from others choices, seems like type f isn’t most common though
Online as in this website? Or other people talking about other bikes?

Type f seems common on this site, but there’s a multitude of different oils people are using
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Re: Clutch slip!

Post by SS109 »

Strictly Kdx wrote: 09:35 pm Aug 01 2019So basically even after odering “upgraded” clutch springs it is likely the oem springs are bette? And I will have to check the friction plates other than that everything else is up to spec but there are some notches in the clutch basket I’ll post pictures tomorrow when I get to work on the bike, also the oil I’ve just started using has friction modifiers which is deffinetly not good but I’ve never used oil like this before anyway. The basket is indeed grooved or notched, I’ll post pictures tomorrow about it when I get to work
Better is a relative term. So called "upgraded" springs are not needed on a KDX no matter how built it is. Trust me, I've built two highly modified KDX's and neither has needed stronger clutch springs except when running an auto-clutch. Stiffer clutch springs only increase effort at the clutch lever with no real benefit.

If your friction plates are used, they have a minimum wear spec. If they are new, don't worry about it. Same goes for the steels.

Never, ever use any oil with friction modifiers as it will ruin the frictions and possibly even the steels from overheating. The most popular type of ATF used by dirt bike riders is ATF Type F. Yes, it isn't the most common as it's meant for old 60's era Ford cars. That said, B&M Trick Shift and other so called high performance racing ATF fluids are just basically repackaged Type F with the price jacked up. If you can't find Type F go with Dexron/Mercon III.

On the basket you can file down the notches. This will make the clutch engagement a lot smoother and get a little more life out of the clutch basket.
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Re: Clutch slip!

Post by KDXGarage »

Just for fun, do only one change, the oil. See how the different oil affects it, then go for the basket filing.

Wiseco used to make baskets. ProX used to also.
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Re: Clutch slip!

Post by Strictly Kdx »

SS109 wrote: 12:10 am Aug 03 2019
Strictly Kdx wrote: 09:35 pm Aug 01 2019So basically even after odering “upgraded” clutch springs it is likely the oem springs are bette? And I will have to check the friction plates other than that everything else is up to spec but there are some notches in the clutch basket I’ll post pictures tomorrow when I get to work on the bike, also the oil I’ve just started using has friction modifiers which is deffinetly not good but I’ve never used oil like this before anyway. The basket is indeed grooved or notched, I’ll post pictures tomorrow about it when I get to work
Better is a relative term. So called "upgraded" springs are not needed on a KDX no matter how built it is. Trust me, I've built two highly modified KDX's and neither has needed stronger clutch springs except when running an auto-clutch. Stiffer clutch springs only increase effort at the clutch lever with no real benefit.

If your friction plates are used, they have a minimum wear spec. If they are new, don't worry about it. Same goes for the steels.

Never, ever use any oil with friction modifiers as it will ruin the frictions and possibly even the steels from overheating. The most popular type of ATF used by dirt bike riders is ATF Type F. Yes, it isn't the most common as it's meant for old 60's era Ford cars. That said, B&M Trick Shift and other so called high performance racing ATF fluids are just basically repackaged Type F with the price jacked up. If you can't find Type F go with Dexron/Mercon III.

On the basket you can file down the notches. This will make the clutch engagement a lot smoother and get a little more life out of the clutch basket.

Well I already knew about the friction modifiers just didn’t pay close enough attention to it when I bought the new oil, and also i looked at the clutch basket and there were some serious notches in it and I filed them down and that made all the difference in the world so now I’m goin to replace the springs back to oem and work my way back to how it’s supposed to be thanks for the help, btw I had no idea how critical those notches really effected the way the clutch acts
The oil that I switched to also probably helps I’ve been changing the oil that I use to find something that would actually last, that’s why I never had a good choice would atf last longer than regular oil?
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Re: Clutch slip!

Post by Strictly Kdx »

KDXGarage wrote: 01:56 am Aug 03 2019 Just for fun, do only one change, the oil. See how the different oil affects it, then go for the basket filing.

Wiseco used to make baskets. ProX used to also.
Yeah the notches were the real problem, they were horrible. Now as far as oil goes I went back to normal stuff I used but I never found an oil that would last for more than 2 or 3 rides is that all there is to it or is there something that actually last a little while
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Re: Clutch slip!

Post by Strictly Kdx »

kdxsully wrote: 07:56 pm Aug 02 2019
Strictly Kdx wrote: 07:31 pm Aug 02 2019 Thanks I’ll try that first, but I was gonna just use my best assumption based off what I read online from others choices, seems like type f isn’t most common though
Online as in this website? Or other people talking about other bikes?

Type f seems common on this site, but there’s a multitude of different oils people are using


In general for more than just the Kdx model bike and I saw a few threads on thumpertalk and ok I’m goin to that because you’re right it seems that’s the most common but does it last? That’s the only reason I’ve never had a set choice what oil I use
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Re: Clutch slip!

Post by SS109 »

No oil last very long. I get 10 hours out of ATF but most think that is way too long. You can tell when performance starts to fall off, and that's normally about 10 hours for me, so that's when I change it.
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Re: Clutch slip!

Post by KDXGarage »

Transmission oil is cheap. Transmission parts are not. I like to change the cheaper one often. :grin:
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Re: Clutch slip!

Post by kdxsully »

Strictly Kdx wrote: 10:47 pm Aug 04 2019
KDXGarage wrote: 01:56 am Aug 03 2019 Just for fun, do only one change, the oil. See how the different oil affects it, then go for the basket filing.

Wiseco used to make baskets. ProX used to also.
Yeah the notches were the real problem, they were horrible. Now as far as oil goes I went back to normal stuff I used but I never found an oil that would last for more than 2 or 3 rides is that all there is to it or is there something that actually last a little while
Was it just that basket or is the boss notched too? Also, check to see if the gap between your friction plate fingers and the basket is still in spec. I think you can cause some damage over time if it’s out of spec. I’d be on the lookout for a basket.
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Re: Clutch slip!

Post by SS109 »

kdxsully wrote: 07:46 pm Aug 05 2019
Strictly Kdx wrote: 10:47 pm Aug 04 2019
KDXGarage wrote: 01:56 am Aug 03 2019 Just for fun, do only one change, the oil. See how the different oil affects it, then go for the basket filing.

Wiseco used to make baskets. ProX used to also.
Yeah the notches were the real problem, they were horrible. Now as far as oil goes I went back to normal stuff I used but I never found an oil that would last for more than 2 or 3 rides is that all there is to it or is there something that actually last a little while
Was it just that basket or is the boss notched too? Also, check to see if the gap between your friction plate fingers and the basket is still in spec. I think you can cause some damage over time if it’s out of spec. I’d be on the lookout for a basket.
Filing the basket is only a stop gap fix and, yes, it means your basket is out of spec and a new basket is in order. However, many have gotten a lot more life with no major failures from filing the basket even a few times.
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Re: Clutch slip!

Post by SS109 »

KDXGarage wrote: 03:42 am Aug 05 2019 Transmission oil is cheap. Transmission parts are not. I like to change the cheaper one often. :grin:
Curious, what is "often" to you? I'm at about every 3-4 rides or roughly 10 hours most of the time.
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Re: Clutch slip!

Post by KDXGarage »

Around there, usually go by color change. One time, I looked up all the parts prices. It scared me!
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Re: Clutch slip!

Post by Molly's 70 »

I have filed down a few clutch baskets in my life. It's a quick fix that works. Depending on how you ride, it could last awhile. If you plan on keeping the bike, buy a new clutch basket. To me, new clutch parts are great!
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