Author Topic: Koni shock rebuilder?  (Read 5032 times)

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Offline grcamna2

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Re: Koni shock rebuilder?
« Reply #50 on: April 03, 2023, 11:09:37 PM »
It turns out the missing part from my kit is the gummy plastic / rubber washer that dissolves into the oil. It is called a top out washer and may or may not even be used in a particular shock. Most of the photos of freshly taken apart shocks I've found don't even show it in place. 

http://forums.sohc4.net/index.php/topic,189439.msg2201810.html#msg2201810

You say that gummy one usually dissolves? I wonder if you could use another type of quality rubber type for that(or an o-ring?),to replace the one that dissolves ?
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Offline RAFster122s

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Re: Koni shock rebuilder?
« Reply #51 on: April 03, 2023, 11:12:06 PM »
It turns out the missing part from my kit is the gummy plastic / rubber washer that dissolves into the oil. It is called a top out washer and may or may not even be used in a particular shock. Most of the photos of freshly taken apart shocks I've found don't even show it in place. 

http://forums.sohc4.net/index.php/topic,189439.msg2201810.html#msg2201810

You say that gummy one usually dissolves? I wonder if you could use another type of quality rubber type for that(or an o-ring?),to replace the one that dissolves ?

If it dissolves into the oil, then maybe it did and that’s why it is not seen in photos of disassembled shocks?

Kind of chicken and egg conundrum…
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Offline Don R

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Re: Koni shock rebuilder?
« Reply #52 on: April 07, 2023, 10:05:33 AM »
  The plastic doesn't actually dissolve into nothing and vanish, it normally turns to goo and lodges in the oil passages. Mine turned to a sticky substance that caused the piston to seize inside the cylinder.
  My research indicates not every Koni came with top out washers.
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Offline Don R

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Re: Koni shock rebuilder?
« Reply #53 on: May 14, 2023, 10:08:44 PM »
 In response to an earlier question about me saying every aftermarket shock I've bought is junk, in fairness they were not new, they lasted long enough to be old and I was foolish to buy old ones on reputation alone.
 The Koni's had incompatible materials inside, and the top out washers stuck inside the cylinder. Often that part turned to goo and plugged the oil passages, mine just stuck in place. The odd thing is not all Koni's even came with that washer in them.
 The new Koni seals are in, I'm going with 75ml of 10W fork oil. The valving is 2 half turns from max stiffness out of 5 total half turns available.  The bike is a performance 836 with a solo seat, progressive front springs in lowered F forks, +2" swingarm, radial tires.
 I hope it's good because they have to come apart again to adjust since I didn't get the top shock mounts off.
« Last Edit: May 14, 2023, 10:15:20 PM by Don R »
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Offline Terry in Australia

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Re: Koni shock rebuilder?
« Reply #54 on: May 15, 2023, 07:58:37 PM »
I think it’s fair to say that most aftermarket shocks are junk Don, I laugh when I see these young guys spending big bux on unnecessary crap like those electronic speedometers that cost a bomb, then put chinese ohlins knockoff shocks on their bikes.

Of course, Koni’s, Ikons, Girlings etc have always made quality shocks that easily outperform the junk that the factories put on our bikes from new, at a reasonable price. We can’t logically expect them to last 40 or 50 years without some maintenance though, so rubber in contact with oil (not to mention rusty water that eventually seeps past worn seals should be expected.

The good thing is that you’ve actually replaced the rubbers and changed the oil, as opposed to a lot of guys who think that “restoring” old Koni’s just means repainting the springs and polishing the bodies. Good job mate. ;D
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Offline Don R

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Re: Koni shock rebuilder?
« Reply #55 on: May 15, 2023, 09:04:13 PM »
 Thanks Terry, and I'd have to say I think I wasted some money here. I'll take them back apart when I regain enthusiasm for the project or donate them to a museum.
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 You don't need a weatherman to know which way the wind blows.