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2018 Husqvarna Vitpilen 401 and 1981 Kawasaki KZ440B
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Discussion Starter · #1 ·
Hello Everyone!

I am working on a Kawasaki KZ400B and am in need of some help! My forks are bleeding like a sieve. I am aware my left fork is missing a dust cover. The question is, will replacing the top seals (and dust covers) be sufficient for them to be useable or should I start hunting for replacements.

Second issue: I took the clutch cover off last night and this piece is hanging (see picture). It was hanging between the cover and the frame. I have been scouring schematics with no luck. Any help would be much appreciated.

I have included my pics up to this point as well!
Wheel Automotive tire Motor vehicle Tire Vehicle brake
Motor vehicle Automotive tire Automotive exterior Rim Automotive wheel system
Tire Wheel Bicycle Bicycle tire Automotive tire
Tire Wheel Bicycle tire Bicycle frame Crankset
Bicycle Wheel Tire Crankset Bicycle wheel rim
 

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If they are serviceable your forks likely have slide bushings (2 in each side is typical, one top one bottom) When the bushings wear out the seals begin to leak, if you don't replace the bushings and oil frequently enough the lower fork leg hole wears oval and then the lowers are done.
Knock them apart and check the bushings, clean everything inside and out just as you would clean a gun and reassemble with new bushings and seals. Should only take a couple hours to fix and a couple of hours to clean up the mess. ... it's very messy.

Will likely cost about 40$ for the seals and maybe another 80$ for the bushings.
... if it has no bushings that can be replaced, then those are basically disposable forks and if you do replace the seals it won't be long before you are doing them again.

The mystery part with the strange #4 bolt does not look like original, is it even a metric bolt?
 

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2018 Husqvarna Vitpilen 401 and 1981 Kawasaki KZ440B
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Discussion Starter · #3 ·
If they are serviceable your forks likely have slide bushings (2 in each side is typical, one top one bottom) When the bushings wear out the seals begin to leak, if you don't replace the bushings and oil frequently enough the lower fork leg hole wears oval and then the lowers are done.
Knock them apart and check the bushings, clean everything inside and out just as you would clean a gun and reassemble with new bushings and seals. Should only take a couple hours to fix and a couple of hours to clean up the mess. ... it's very messy.

Will likely cost about 40$ for the seals and maybe another 80$ for the bushings.
... if it has no bushings that can be replaced, then those are basically disposable forks and if you do replace the seals it won't be long before you are doing them again.

The mystery part with the strange #4 bolt does not look like original, is it even a metric bolt?
Thanks! Do you have a good site to get the bushings and seals from?

The bolt is a 10mm. I am at a loss as to what that would be.
 

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I think you might better knock them apart and see what's in there first. Parts are going to be difficult to source by a kawasaki part number and you might be looking at needing to substitute anything that's worn out.

I haven't been impressed with the aftermarket so called rebuild kits, half the time they contain parts that don't fit well. More often then not I have had to hand file and fit the fork bushings because they didn't work as delivered.

Pretty sure you can discard that mystery part.
 

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Pretty sure that is the spring attachment bracket for the center stand
 
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2018 Husqvarna Vitpilen 401 and 1981 Kawasaki KZ440B
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Discussion Starter · #7 ·
Awesome! Thank you all!

Hopefully I will find some time to get the forks torn down this weekend.
 

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If the forks are like my old bikes were then the seal is going to be stuck. I used penetrating oil and I used heat (blowtorch) and careful prying and very careful cutting on the seal to get mine out. You can do it without damaging the seal bed. I got oem replacement seals from ebay. Trials is right, it is a mess!
 

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With most forks the trick is to get the big bolt and copper washer out the bottom of the lower fork leg.
After that, if they have bushings, you remove the wire retaining clip from above the seal, then you just top out the stanchion tube with a firm bump a few times for the seal and everything else to pop out.
It's easy after the first time, the old forks are even symmetrical, on some of my bikes they have a spring in one side and a shock is in the other fork , lol so it takes twice as long to learn.

I like doing RSU forks, it's always a challenge to see how good you can get them. I fit them dry and then do a full assembly after the slide bushings feel perfect :cool: then you fit the seal to make sure it slides nice, and Never forget to put the bell washer under the seal the right direction (cone big end up), because the steel has to hit the outside rim only on the fork seal.
 

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Discussion Starter · #10 ·
Thanks for all the tips! Will it be fairly obvious if my seals and bushings are shot?
 

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Thanks for all the tips! Will it be fairly obvious if my seals and bushings are shot?
Yes, all the black nylon coating will be worn off.
Save the old top bushing (if so equipped), they are handy for re-inserting the new one and not damaging it.

Seals you can examine the inside lip under a stereo microscope and tell if it's damaged.
most people just replace them. They come in different quality and type, watch out for that, I've got a new pair in the shop now that are almost garbage right out of the box. SKF seals never seem to fail on quality at about twice the price of the ones in bubble pack.

... so are you trashing the heavy steel centre stand? she must have been bouncing up and down pretty good on the potholes I bet lol
 

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Discussion Starter · #12 ·
Yes, all the black nylon coating will be worn off.
Save the old top bushing (if so equipped), they are handy for re-inserting the new one and not damaging it.

Seals you can examine the inside lip under a stereo microscope and tell if it's damaged.
most people just replace them. They come in different quality and type, watch out for that, I've got a new pair in the shop now that are almost garbage right out of the box. SKF seals never seem to fail on quality at about twice the price of the ones in bubble pack.

... so are you trashing the heavy steel centre stand? she must have been bouncing up and down pretty good on the potholes I bet lol
That is where I am leaning. The spring is still on the other side so it was staying up alright, but no need to have that and the kick stand!
 

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Discussion Starter · #13 ·
It seems to be the consensus on my build thread that I should install different wheels and brakes. This is a very noob question so please bear with me. Since my front suspension is still pouring fluid all over my floor, is it possible to find forks of the same diameter from a more modern bike and utilize the stock triple tree? If so, I assume I could find front end parts (wheel, brakes) to match. I don't have a lot of money to put into the bike, so please let me know if I am looking at big money to even consider this. Thanks all!
 

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Cheapest is to work with what you have.
Did you knock them apart and completely clean them up inside yet?
 

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It seems to be the consensus on my build thread that I should install different wheels and brakes. This is a very noob question so please bear with me. Since my front suspension is still pouring fluid all over my floor, is it possible to find forks of the same diameter from a more modern bike and utilize the stock triple tree? If so, I assume I could find front end parts (wheel, brakes) to match. I don't have a lot of money to put into the bike, so please let me know if I am looking at big money to even consider this. Thanks all!
Hi mate, a good question.
I will go over the immediate things to consider which will get you on the board.
There will always be further fettling after the initial fitment if you go this route.

Finding forks with the same stantion diameters will mean that they will slide straight into the triples no problem.

Now they are in they may differ in two ways.

FORK LENGTH
Unless you are a suspension guru i would try and source shocks as close to the stock length as possible. This will keep rake and trail numbers as intended by the smart engineers at whatever factory your bike was born in.

DISTANCE BETWEEN THE FORK LEGS
with your new shocks on, the same length as the one that came with the bike, the forks will almost certainly be a different width apart.
This could just be as simple as making a couple of spacers to run on the axle.
The most difficult thing is to get the brakes to line up. Whether that be spacing the discs or custom caliper mounts. Etc.

Its all doable but requires a lot of thought and plenty of thinking beers.

For my money i would find the complete front setup from a bike with modern right way up forks and bolt that up. That way you know everything will fit thats bolted on below the triples.

This way comes with its own challenges mainly the stem length and diameter of the triple to the bearings.
Also Don't forget fork offset. The difference between the centreline of the triple stem and the fork centres. The same length of fork with different offset will yield different steering geometry numbers.

As you can see there's lots of things to consider when doing a fork swap.
Its definitely a good option and can be a performance upgrade.

The guys that track these bikes may have a tried and tested bolt on upgrade that is a common setup.
 

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Any forks bought new or used still need regular service, needing new seals and bushings is going to happen plenty, you might better get good at fixing them.
 
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