Fork issues

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Fork issues

18 Mar 2017 19:12
#757068
Hey guys, I'm fixing up an '81 KZ750E2. Working on the frame I discovered that I have one bent fork tube. So I hit up eBay and was able to find some NOS OEM inner fork tubes. The part number is 44013-1076. They came with the lower bushings, which is good because the old ones were worn to almost metal.

So here's the problem. When I pulled the old inner tubes out the bushings and fork seals stayed in the outer tubes. I'm not used to that but was like, oh well, that must be the way these old forks are.

I started assembling them and discovered that the inner tube bushing is slightly larger diameter than the old one, and big enough that they wont fit past the outer tube bushings. That outer tube bushing is pressed in and I can't seem to get it out without destroying it. I'm now reading that you have to replace the whole outer tube if that bushing wears out. I find this hard to believe, but damn I can't figure out how to get them out.

Here's my thoughts, but I'll need some mechanical engineering help here: The outer is aluminum and the bushing is steel. To aid in removal of this outer tube bushing, should I heat the assembly or cool it? The expansion coefficient is different for the two metals but I'm not sure which way to go.

Has anyone ever successfully removed and replaced these bushings?
Greg

1981 KZ750E (Work in progress)
1998 VTR1000F
2004 CBR1000RR
2014 Ninja 650 ABS

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Re: Fork issues

18 Mar 2017 19:18
#757069
One more thing, does anyone have a parts fiche diagram and listing for the '81 KZ750E, specifically for the forks?
Greg

1981 KZ750E (Work in progress)
1998 VTR1000F
2004 CBR1000RR
2014 Ninja 650 ABS

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Re: Fork issues

19 Mar 2017 09:07
#757127
Thanks for the links, Michael. I've been to both websites and others but they don't have a diagram for the '81, only a parts list. The part numbers differ between '80 and '81.

There are TWO part numbers for the inner fork pipe, 39093-1067 and 44013-1076. What's the difference? Apparently the diameter of the lower bushing!
Greg

1981 KZ750E (Work in progress)
1998 VTR1000F
2004 CBR1000RR
2014 Ninja 650 ABS

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Re: Fork issues

19 Mar 2017 10:46
#757135
I have looked up your numbers for the inner fork tubes (39039-1067 and 44013-1076) in the Kawasaki Model Application Guide for US parts and the 39039-1067 is not listed...which means that the fork tubes with that number were for non-US models (although the Guide does include some Canadian models). You do not say where you are located in your avatar.

Not sure why the diagrams for the Kawasaki KZ750-E2 are incomplete.
Michael
Victoria, Texas

1982 GPz750
1977 KZ1000A
1978 KZ1000A
1982 GPz1100
1975 Z2A

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Re: Fork issues

19 Mar 2017 12:27
#757145
I have a US KZ750E, located in MO.
Greg

1981 KZ750E (Work in progress)
1998 VTR1000F
2004 CBR1000RR
2014 Ninja 650 ABS

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Re: Fork issues

22 Mar 2017 16:19
#757414
I can have the fork tube straightened but I need to know what the part number is for the lower (inner) bushing. Does anyone know the correct part number for this?

Or does anyone here have the correct bushings laying in the garage? Correct dimensions are 1.400" OD, 1.335" ID, 0.777" width.
Greg

1981 KZ750E (Work in progress)
1998 VTR1000F
2004 CBR1000RR
2014 Ninja 650 ABS

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Re: Fork issues

23 Mar 2017 00:39 - 23 Mar 2017 00:40
#757447
I am maybe wrong with my translation but the service manual says, if the inner and outer bushing are damaged you have to
replace the inner and outer tube assembly (as a unit). The bushings are not sold separately???

Last edit: 23 Mar 2017 00:40 by Scirocco.
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Re: Fork issues

23 Mar 2017 18:11 - 23 Mar 2017 18:11
#757498
I agree it states this in the manual, but then why would there be parts listed for one of the bushings? And that part number is only listed on the '81, not the '80. The '81 listings don't have a parts diagram to go with the parts list so I don't know if it's the upper or lower bushing! This is so frustrating!!!
Greg

1981 KZ750E (Work in progress)
1998 VTR1000F
2004 CBR1000RR
2014 Ninja 650 ABS
Last edit: 23 Mar 2017 18:11 by hawkrider.
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Re: Fork issues

24 Mar 2017 08:17
#757550
Hi hawkrider,
Try contacting Forking by Frank. They may be able to help with parts / advice.
franksforks.com/

Good Ridin'
slmjim & Z1BEBE
A biker looks at your engine and chrome.
A Rider looks at your odometer and tags.

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Re: Fork issues

25 Mar 2017 22:47
#757711
Call Race Tech, they have the best quality fork bushings I've found. They will help you find the correct parts even if your bike is not listed on their sight.
1980B4 1000
1978 Z1R
1978 B3 750
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Re: Fork issues

12 Apr 2017 18:33
#759060
We ended up machining down the bearing surface of the two NOS fork tubes and carefully cutting down the diameter of its bushings to fit. They work great and the suspension feels pretty good (for what it is) using Repsol 10wt fork oil.
Greg

1981 KZ750E (Work in progress)
1998 VTR1000F
2004 CBR1000RR
2014 Ninja 650 ABS

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