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2008 KX250F Shock Confusion

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I'm in the middle of rebuilding the shock on an 08 KX250f. The previous owner had removed the peening on the shock shaft nut and I assume he messed with the shims. I'm not real sure how to properly measure these things or what they are supposed to be from stock. I figured since I'm this deep into it, I might as well adjust the shims. I'm 205 lbs and a novice motocross rider. Has anyone tried a stack that worked out pretty well for them? I'm also planning on putting a 5.7 spring on it as well. I can't really afford putting a gold valve in it.

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The '07 and '09 shock stacks seem to be listed in these archives: 

Compare those with the shims you currently have.

Edited by mlatour

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I finally measured the shims and this is where I am:

nut

baseplate 29.5 x 3 

26 .3

28 .3

30 .3

32 .3

34 .25

36 .25

38 .25

40 .25

25 .1

40 .20 (2)

piston- large holes were going towards rebound 

44 .25 (6)

44 .2 (2)

37 .15

26 .10

44 .15

42 .20

40 .25

38 .25

36 .25

34 .25

32 .20

30 .20

28 .20

26 .20

24 .20

22 .20

25 .50

38 .25

40 .10 (2)

baseplate 44.5 x 5

44 .25

 

it varies from stock from what I can tell. Do I need to rearrange anything before slapping a 5.7 kg spring on it? Any guidance is appreciated. I'm pretty lost. 

Edited by Pastmyprime214

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You will need many more 40.2 for the rebound , like 7 in total , comp hard to say without thickness of the shims

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Don't apply a great deal of pressure.  Zero it out with a slight amount of pressure and measure the shims with the same amount of pressure.  Check your measurement with a feeler gauge of known thickness to make sure you're getting it right.

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I had a YZ 125 16 years ago that pro action did before I bought it. I really liked how forgiving if was it I cased anything which I did a lot. That was also about 50 lbs ago. Will any companies lay out a shim stack for a specific ride without buying a 170 gold valve?

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Std
44x.25 (7)
44x.20 (2)
37x.15
22x.20
44x.25
42x.25
40x.25
38x.25
36x.25
34x.25
32x.25
30x.25
28x.25
26x.25
24x.25
22x.25
25x.60
44.5x.50
44x.30

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With a 5.7 you need t least 6 face shims on rebound

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9 hours ago, mog said:

With a 5.7 you need t least 6 face shims on rebound

Do you happen to know the stock rebound stack for the 08?

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I don't sorry but here is a 2010 it's way stiffer than yours

.20x40
2-.25x40
.10x24
.30x40
.30x38
.30x36
.30x34
.30x32
.30x30
.30x28
.30x27
.30x26

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I found the 08 stock rebound stack and I'm pretty dead on with it. I'll add 4 more 40.2 for the 5.7 spring rate. Will the added shims screw up the alignment to the threads on the shock shaft nut?

Do I need to alter the compression as well from stock? What's a good source to buy individual shims?

Sorry for all the questions, but I'm definitely learning a ton.

Edited by Pastmyprime214

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Compression is based more on speed than weight , most can get away with using the same comp with a stiffer spring, should be enough space on the shaft

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On 6/22/2017 at 1:13 AM, mog said:

Compression is based more on speed than weight , most can get away with using the same comp with a stiffer spring, should be enough space on the shaft

Mog,

is it ok to mix the shims that are in the stock stack with new ones from suspension direct? They have most that I need to re-build a new stack with stock specs except for a few odd sizes like the 37x15 crossover. Also have to add more on the rebound side. Any problems with this?

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