Fork Disassembly

  • Tiger2126
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Fork Disassembly

15 Sep 2020 16:25
#835122
I have a 81 kz650 and I'm trying to replace the fork seals. The problem I'm having is that the allen head bolt on the bottom of the forks is just spinning the insides. Any tips as to how to remove the stubborn bolt?

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  • 650ed
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Re: Fork Disassembly

15 Sep 2020 17:07
#835125
When I replaced the fork seals on my 1077 KZ650 I made a tool to hold things from spinning (See image below). Later, a company offered a tool that would do the same thing (see "DAMPING ROD HOLDING TOOL" at www.racetech.com/page/id/70 ). Before trying either tool you need to first determine if your bike's forks have smooth round holes or hex shaped holes. I know at least some of the later bikes had hex shaped holes and I don't think either tool I mentioned will work on those. Ed

1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)

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Re: Fork Disassembly

15 Sep 2020 17:36
#835128
I stuck a camera down the tube. it looks like a tool like that would do the trick, I don't immediately have the stuff for it, but I'm sure it would work. Thank you!

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  • martin_csr
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Re: Fork Disassembly

15 Sep 2020 18:14 - 15 Sep 2020 18:16
#835133
1981 KZ650-CSR forks.
The head of the inner cylinder looks just like a 12-pt 19mm socket. 19mm = 3/4" approx.
I used a LH threaded bolt w nuts & long ratchet extensions. Some guys weld a nut to the threaded end of a long bolt.


Last edit: 15 Sep 2020 18:16 by martin_csr.
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  • Irish Yobbo
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Re: Fork Disassembly

15 Sep 2020 18:38
#835135
I've managed before by using a broom handle on the inside and an impact wrench on the nut. I've also manage just with an impact wrench and nothing else in the past.
1981 KZ750 LTD

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  • martin_csr
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Re: Fork Disassembly

15 Sep 2020 18:41 - 16 Sep 2020 05:40
#835136
I don't have an impact wrench. The first time doing the job, I used a hardwood rake handle carved into the shape of a cone. But the tool in the pic fits perfectly & makes disassembly easy.

Tiger2126: just an fyi. for the bottom allen bolt, you should use an 8mm brake caliper allen socket or hardened allen socket. A cheap allen wrench could twist & damage the bolt head.
Last edit: 16 Sep 2020 05:40 by martin_csr.
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  • Highway Magician
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Re: Fork Disassembly

16 Sep 2020 08:50
#835163

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Tiger2126 wrote: I have a 81 kz650 and I'm trying to replace the fork seals. The problem I'm having is that the allen head bolt on the bottom of the forks is just spinning the insides. Any tips as to how to remove the stubborn bolt?

Hand-held impact tool or an electric / air impact gun:

Put the fork upside down on a piece of wood and apply some downward pressure

Use the hand-held or air / electric impact gun to remove the bottom bolt.
Motorcycle builder since 1973. Master Tech. Current bike: 1982 GPZ1100B2.

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  • Mikaw
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Re: Fork Disassembly

16 Sep 2020 11:39
#835174
Just my $.02 I’ve had hit and miss success with that method. Sometimes I get lucky. But it’s not 100% effective for me. So I’ve purchased or made the correct tool to hold the damper rod.
1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.

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  • Highway Magician
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Re: Fork Disassembly

16 Sep 2020 22:20
#835200
The best results will be from using a really good impact gun.

I recently used this one to remove the pesky, threaded fork top caps from my '82 GPZ1100.

They literally came out in a couple of seconds. It has 1050 ft. lbs. of bolt breakaway torque.

It's heavy but incredibly powerful.

www.harborfreight.com/85-amp-corded-12-i...ct-wrench-64120.html
Motorcycle builder since 1973. Master Tech. Current bike: 1982 GPZ1100B2.

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  • Bozo
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Re: Fork Disassembly

17 Sep 2020 03:03
#835203
Most of the time I just loosen the allen screw while the fork is assembled with spring, then I pull the fork apart
First Permanent ride the Z1R since Dec1977 (220,000km) as of June 2015
Second permanent bike 1989 FJ1200 dyno'd 140RWH, great bike.
Third ride is now the Frankenstein 1981 GPZ1100B1, 1983 fully recon motor fitted LOVE THIS BIKE
Forth my work bike FJ1200 1989 (same type as FJ above)

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  • Tiger2126
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Re: Fork Disassembly

17 Sep 2020 15:10 - 17 Sep 2020 15:11
#835236
This is what I came up with, bolt welded to some rebar with a rebar handle welded to it, it works pretty good, I just wrapped some tape around it so it wouldn't damage anything inside. I had tried all the non-special tool methods before making a post, but there's a good chance that the forks have never been apart before I got a hold of the bike. Thanks for all the help with this, this is a pretty cool community!

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Last edit: 17 Sep 2020 15:11 by Tiger2126. Reason: the photo didn't get attached for some reason

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  • d4rkmatter
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Re: Fork Disassembly

25 Jan 2021 10:16
#842371
I just discovered a pretty good trick on my K750H and needed to share.

Take a 5/8" spark plug socket and remove the rubber guide from it. Put it on your driver backwards and use a bunch of extensions to get it down the tube.
Worked like a charm for me.

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