1984 KDX200 shock rebuild

Discussion specific to the various air-cooled KDX models sold in the USA
SRRobirds
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1984 KDX200 shock rebuild

Post by SRRobirds »

So a couple observations and a question about the rebuild of my 1984 KDX200 shock. The observations are mentioned just to help others who may be tackling this...

Observation 1: For some reason, my shock has a press fit cap, like newer models, rather than screw on as mentioned in the manual (It also has only one hole in the cap rather than two). I struggled to screw it off until it finally moved enough to see there were no threads.
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Observation 2: Also, for some reason, my shock has two circlips holding the piston seal head rather than one as mentioned in the manual. My language got pretty salty until I realized there was another circlip!
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Question: Since I am replacing the piston seal head, I'll need to remove either the nut by the piston or the clevis. The nut on my piston shaft has a plate over it, which is different from the punched threads I ground down on my 86 KDX. How is the plate removed so that I can access the nut? Would it be easier to remove the clevis and if so, how should I position the damping dial?
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Thanks for any guidance you can give me!
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Re: 1984 KDX200 shock rebuild

Post by KDXGarage »

Can you post a picture of the whole body and whole shaft?
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Re: 1984 KDX200 shock rebuild

Post by SRRobirds »

Here you go - thanks for thinking about this.
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Re: 1984 KDX200 shock rebuild

Post by KDXGarage »

Is the end of the shaft not peened over like the newer shaft ends? On those, I just shove some grease down inside to catch the filings and flat grind it down.

It almost looks like a Showa, where it had the reound needle holding portion at the end and one would have to grind it at an angle to keep the parts inside. Look on youtube for the Race Tech shock videos. The two styles are shown.

Someone on eBay has a shock for sale, showing the cap does not have the two holes. :hmm:

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wfopete
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Re: 1984 KDX200 shock rebuild

Post by wfopete »

Following. I just rebuilt my 84 KDX200 shock and something is wrong. Very hard with almost no movement!
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2006 300XC, 1980 YZ465, 1971 CZ250, 1973 Penton Jackpiner (2), 1970 Hodaka ACE 100, 1974 YZ250, 1973 CR250, 1985 XR350R, 1986 XR250R, 1974 TM400, 1975 TS400, 1974 Husky CR250, 2012 Yamaha Tenere', 1984 KDX200
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Re: 1984 KDX200 shock rebuild

Post by KDXGarage »

How was it before the work?
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Re: 1984 KDX200 shock rebuild

Post by wfopete »

I don't know if you are talking about mine but my shock got a new spring and while I had it off I put in a new head seal and oil. The bike is new to me though. I understand the revivor piston needs to be at a certain spot when adding oil. I don't have a manual that explains the rebuild procedure though.
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2006 300XC, 1980 YZ465, 1971 CZ250, 1973 Penton Jackpiner (2), 1970 Hodaka ACE 100, 1974 YZ250, 1973 CR250, 1985 XR350R, 1986 XR250R, 1974 TM400, 1975 TS400, 1974 Husky CR250, 2012 Yamaha Tenere', 1984 KDX200
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Re: 1984 KDX200 shock rebuild

Post by KDXGarage »

The 1979 - 1987 manuals seem to be pretty cheap on eBay. You might want to look on there.

Did it move smoothly during the rebuild?
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Re: 1984 KDX200 shock rebuild

Post by wfopete »

It seemed to but I went into it a couple of times trying to get it right. I'm pretty sure we put too much oil in and I'm getting a hydro lock condition.
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2006 300XC, 1980 YZ465, 1971 CZ250, 1973 Penton Jackpiner (2), 1970 Hodaka ACE 100, 1974 YZ250, 1973 CR250, 1985 XR350R, 1986 XR250R, 1974 TM400, 1975 TS400, 1974 Husky CR250, 2012 Yamaha Tenere', 1984 KDX200
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Re: 1984 KDX200 shock rebuild

Post by KDXGarage »

I have never fooled with a piston reservoir. Sorry to not be of more help.
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Re: 1984 KDX200 shock rebuild

Post by wfopete »

Well today I went back into the shock reservoir. Set the piston, added correct amount of oil and dropped the pressure to 135psi. Still not right. I'm suspicious that the shock may have been assembled wrong. Maybe a shim was put in the incorrect order.
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2006 300XC, 1980 YZ465, 1971 CZ250, 1973 Penton Jackpiner (2), 1970 Hodaka ACE 100, 1974 YZ250, 1973 CR250, 1985 XR350R, 1986 XR250R, 1974 TM400, 1975 TS400, 1974 Husky CR250, 2012 Yamaha Tenere', 1984 KDX200
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Re: 1984 KDX200 shock rebuild

Post by KDXGarage »

perhaps blocking the ports?

rebound needle working properly?
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Re: 1984 KDX200 shock rebuild

Post by wfopete »

Yeah, I think so. Tore it down today and paid more attention to the itty-bitty parts and what could have gone wrong. I reassembled it and now it's a lot better. I'll race it next weekend and see how it feels but it will likely come a part again. But for now it works.
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2006 300XC, 1980 YZ465, 1971 CZ250, 1973 Penton Jackpiner (2), 1970 Hodaka ACE 100, 1974 YZ250, 1973 CR250, 1985 XR350R, 1986 XR250R, 1974 TM400, 1975 TS400, 1974 Husky CR250, 2012 Yamaha Tenere', 1984 KDX200
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Re: 1984 KDX200 shock rebuild

Post by KDXGarage »

Well I am glad you got it going. Stay safe and have fun at the race.
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Re: 1984 KDX200 shock rebuild

Post by wfopete »

The shock worked "Ok" but it could be better. I believe it rode a bit soft in the first half of travel although the sag was set at 100mm. Does anyone know what manual (factory or aftermarket) specifically addresses the shock rebuilding procedure for this year? I doubt the factory owners manual would but if I'm wrong, say so.
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2006 300XC, 1980 YZ465, 1971 CZ250, 1973 Penton Jackpiner (2), 1970 Hodaka ACE 100, 1974 YZ250, 1973 CR250, 1985 XR350R, 1986 XR250R, 1974 TM400, 1975 TS400, 1974 Husky CR250, 2012 Yamaha Tenere', 1984 KDX200
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Re: 1984 KDX200 shock rebuild

Post by KDXGarage »

I can't remember if the manual shows it or not. I know the 87 manual does.

What is your weight in full riding gear? You might need a stiffer spring in front and rear.
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Re: 1984 KDX200 shock rebuild

Post by wfopete »

I already replaced the OEM spring with one (Race Tech) for my weight/riding. I think I'll just get a Clymer manual off evil bay, it wouldn't be the worst thing I've done. The shock valving seems rather primitive, I may end up replacing it with a new shock this year.
Last edited by wfopete on 08:50 pm Nov 09 2021, edited 1 time in total.
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Re: 1984 KDX200 shock rebuild

Post by KDXGarage »

It is indeed primitive compared to today. I doubt it was cutting edge in 1983 when made.

I have never tried it, but have been curious about putting a YZ85 40mm piston for my '87 and best guessing the valving. Those pre-1989 shock bodies may not be hard anodized like the 1989+ bodies.
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Re: 1984 KDX200 shock rebuild

Post by wfopete »

I cycled shock fluid through mine twice it was so gray colored and my shock was rebuilt a couple years ago.
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2006 300XC, 1980 YZ465, 1971 CZ250, 1973 Penton Jackpiner (2), 1970 Hodaka ACE 100, 1974 YZ250, 1973 CR250, 1985 XR350R, 1986 XR250R, 1974 TM400, 1975 TS400, 1974 Husky CR250, 2012 Yamaha Tenere', 1984 KDX200
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Re: 1984 KDX200 shock rebuild

Post by wfopete »

My Clymer KDX200 Manual came in today but unfortunately it does not address the shock shim stack or valving :sad:
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2006 300XC, 1980 YZ465, 1971 CZ250, 1973 Penton Jackpiner (2), 1970 Hodaka ACE 100, 1974 YZ250, 1973 CR250, 1985 XR350R, 1986 XR250R, 1974 TM400, 1975 TS400, 1974 Husky CR250, 2012 Yamaha Tenere', 1984 KDX200
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