Author Topic: 1980 KX250 A6  (Read 2692 times)

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Offline Cwood

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1980 KX250 A6
« on: April 07, 2019, 10:31:39 AM »
Building an KX250-A6 for some VMX racing.  I’m looking for a rear replacement shock.  The 1980 is not re-buildable but the 1981’s are. KX 250 or 420 will work...   Or a suitable aftermarket replacement.   Any ideas or good uses shocks/codes?   Any other years that may work?

Offline KXDINO

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Re: 1980 KX250 A6
« Reply #1 on: April 18, 2019, 09:00:54 PM »
81 shock would bolt up , and i would compare sizes up to 86 as 87 onwards they changed to under swingarm linkage and if they do bolt up then you would have to test ride and most likely alter the valving as the rising rate will or could be different as well as spring rate.but that the fun of changing parts.

Offline motojason

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Re: 1980 KX250 A6
« Reply #2 on: May 09, 2019, 03:11:07 PM »
Only 81 KX250 or 81-82 KX420 stock shocks can work. Nothing later will be close. The linkage design on the first generation of Uni-Trak bikes is very different from the later rocker type Uni-Traks from 82-85 with welded box section rockers. The spring rate on the 81 250 or 81-82 KX420 is around 8.2 kg/mm the later KXs used a shock spring rate around 5.0 kg/mm and different valving.

I just received my shock from Noleen for my 81 KX250. Clark has all the specs and can build one for you. Looks great. Plan to race at Mill Creek with it next weekend.       
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Offline KXDINO

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Re: 1980 KX250 A6
« Reply #3 on: May 09, 2019, 04:03:42 PM »
good info, thats what this site about.