'86 - Down the Rabbit Hole

Reference and discussion for the various air-cooled KDX models
Clatter
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Re: '86 - Down the Rabbit Hole

Post by Clatter » 04:21 pm Mar 05 2019

Last weekend started some top-end assembly..
Because we are still waiting on a huge order of misc little motor internal parts i.e. bearings,
We'll do what we can to get some sub-assemblies ready for later.

Cleaning the KIPS valves and getting their associated parts ready took a good long time.
The stuff gets baked into those valves like nobody's business..
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The POR-15 paint was a bit disappointing.
It flakes off in spots pretty easy.
It was done according to the directions - to the letter,
Stuff was prepped perfectly.
It just kind of sucks..
Look closely and you'll see a bunch of tiny touch-ups.
I will never use it again.
Don't let them sell you rattle-can as anything else but;
Rattle-can is still rattle-can.

Anyhow,
Using fresh fasteners and gaskets and all is just so satisfying.. :supz:
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These little rubber spacer plug things between the fins just wouldn't give up their dirt;
The mud had been baked on forevermore.
Finally it came to me to use hand cleaner, and let them soak in it overnight.
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Also picked up the silver stuff from Grizzly Powder Coating here in Santa Cruz.
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Brook puts a lot of these boys to shame with her work..
All of the tapped holes and places where things need to NOT have coating were masked perfectly.
Frame numbers nice and legible, she just nutted it.

Looks like some more assembly in our future. :boogie:

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Re: '86 - Down the Rabbit Hole

Post by KDXGarage » 05:30 pm Mar 05 2019

Congratulations on the continued work.

I am sorry to hear that the POR-15 turned out poorly. I was curious about it.

Good job to clean all the KIPS parts.
Thank you, Julien D for keeping the site going.

If you have a question about YOUR BIKE, please tell us what model YOUR BIKE is. :-)

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Re: '86 - Down the Rabbit Hole

Post by Clatter » 12:09 pm Mar 11 2019

WhooHoo!! A whole weekend! :supz:

Saturday started early early, with a previously-cleaned-and-sealed fork assembly or two.
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Having had the sliders blasted as part of the powder-coat process,
It was a task to make sure ALL of the grit got chased out of the leftover oil goo at the bottom..

That led to some bearings and trees,
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Which led to a fork!
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The thing feels nice and plush. :grin:
Pumping them thru to get the oil in and the bubbles out is certainly one of life's great joys.
You can feel things start to work like they're sposeta'.. :cool:

Saturday was spent digging thru boxes of parts and finding things and wire-wheeling fasteners and whatnot.
Got the dog-bone and a few swingarm things assembled but didn't get a pic.

Sunday, my friend William came by.
He's an A&P certified guy, long-time hot rodder, confederate air force guy..
He even went to England to school for motorcycle suspension.
Not a bad kind of friend to have come over and help out.. :boogie:
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Didn't stop us from being stupid on disassembly;

The top of the cartridge area threads on with this '85-style shock here,
Doesn't pry off like we're trying to do.. :oops:
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In all fairness, if it HAD been an '86 shock, it woulda pried off like that.
And,
Luckily,
We figured it out before mangling the thing too badly.

Like everything else on this bike,
The number of broken and battered parts was large.
See how the bumper is split in half,
and even the little plastic dampener adjustment knob is broken.. :evil:
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The bore looks good, so if we can get parts, it'll get rebuilt...
If anyone knows where to get specific stuff like this, I'm all ears.
Another rabbit hole to go down deep within!! :doh:


Feeling like succeeding at something, we dove in to front brake rebuild.
How you like this redneck engineering right here?
Front brake caliper leaking, Bubba?
Just go ahead and bloob a bunch o' black RTV all over the outside of the caliper,
That'll fix 'er good! :rolleyes:
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William went to filing down most of the gouges and damage that were all over the parts.
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I rounded up any small parts that i could find that might need some paint,
And William got them ready.
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Decided to go ahead and mix up some real paint..
If we woulda just used rattle-can, no doubt the brake fluid would have just washed it off with the first spill.
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It's gloss black, not semi-gloss which i would have preferred,
But oh, well; Git 'er done!
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Here's master cylinder hardware all cleaned up on the left,
caliper hardware all cleaned up on the right,
And a totally-wrong rebuild kit some dorks on ebay sold me on top.
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Don't you just hate that?
They sell it to you knowing full well it's the wrong stuff; knowing you won't get to installing until it's too late,
Or won't bother dealing with a refund, or..?



Another fun find..
Was going to put the rear hub all back together, and found this:
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The snap ring groove that holds the bearings in place is completely broken away! :roll:

No wonder the spacer inside the hub was all chewed up!
They were just riding it like that..
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So anyways,

The battle rages on..


Any chance one of you out there has a rear wheel you'd sell me?

Maybe one of you guys who converted to disk has one lying around?
:prayer:

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Re: '86 - Down the Rabbit Hole

Post by pkenney » 08:49 pm Mar 11 2019

My stock rear hub had the same problem so I put it on a lathe to dig the groove a little deeper.
It wouldn't think it would take much to keep the circlip/bearing in place. I don't know why they all break in the same way.
I do have another hub that I think was in the same condition but I think the sprocket side bearing bore was wasted too.
I will check next time I'm in the garage.

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Re: '86 - Down the Rabbit Hole

Post by KDXGarage » 08:59 am Mar 12 2019

Man. Isn't it nice to correct previous owners' mistakes? UGH!

Here's a picture of the ring nut wrench for that shock. (taken off eBay seller)

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Perhaps looking for a 1986 - 1988 shock would help. You can get a bumper from most places, including Parts Unlimited or Tucker dealers.

www.racetech.com will have several parts.
Thank you, Julien D for keeping the site going.

If you have a question about YOUR BIKE, please tell us what model YOUR BIKE is. :-)

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Re: '86 - Down the Rabbit Hole

Post by Clatter » 12:30 pm Mar 16 2019

The tides are starting to turn..

Got in a huge order from Greg at Off-Road Innovation.
Greg is the MAN who can get almost everything for these..

After like 40 e-mails and a dozen phone calls, parts start streaming in, with more to come.

Clean off powder-coat, and push nice new parts in place..
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Man, this one wanted to fight!
Funny how one little thing will take longer than all others combined. :evil:
Great moment of victory in this shot..
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Mocked up case to get shock brackets in, making sure it all fits together.
Cleaning up powder coat, so things assemble easily beforehand.
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Worked late into the night, prepping the case halves with new bearings and seals.
Had to resort to some hackage, because I don't have a proper small puller.
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Took forever to clean grinding grit out of the case,
Without having the carb cleaner wash new paint off..
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Got the cases and covers prepped with new bearings and seals way after midnight.
Was getting tired, and had a few.. :drinkers:
Good to put off doing any actual assembly, until a fresh head can be found upon my shoulders.
Or at least nearby.. :blink:
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Will be doing a big bench and fastener cleanup session,
Lie everything out in order,
To start assembly hopefully soon..

Kinda scary, because i have never done one of these,
And everything on this bike is suspect at this point.
Going to be a real long/deliberate assembly session to get everything together right!

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Re: '86 - Down the Rabbit Hole

Post by KDXGarage » 05:01 pm Mar 16 2019

Keep up the good work!
Thank you, Julien D for keeping the site going.

If you have a question about YOUR BIKE, please tell us what model YOUR BIKE is. :-)

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Re: '86 - Down the Rabbit Hole

Post by Clatter » 11:25 am Mar 17 2019

Hey, thanks, I think I will.! :grin:

Here was the big/scary part of the assembly; lower end -and- transmission..!

This will be a big long post, so if you are in a hurry, don't bother. :grin:

I figured it would be good to catch some details here, because I'm a first-timer with these things.
Having a newbie post up -should- in theory be more helpful to other beginners,
Because we assume a lot less than someone who knows, right?


Had to clean up the bench as much as possible..
Don't know why, but having just what's happening in front of me, instead of other stuff, helps.
I just get so distracted.. Must be ADD or OCD or something.
Also drves me nuts when i need to set something down and can't!

Anyways, :rolleyes: The old silver lump on the left, along with the manual, and a clean spot (if possible),
Helps me (try to) stay focused... And figure out how this thing goes together. :blink:
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My manual is just a Clymer, that leaves things out a lot of the time.
Luckily there are the factory parts diagrams online,
Where i could be confident that the shift drum and linkage were together correctly.
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Having both the old lump trans and the 'newer' one from e-bay side-by-side, to:
1. Make sure they are both together the same (in case something was assembled wrong).
2. Find the best parts from the two.
Turns out the e-bay trans had all of the tidiest dog teeth, and least scoring or heat scuffs.
They both measured out about the same, at least in the places where you can get measurements,
Like the fork slider ares and the shift drum slots..
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A trans-only mock-up was helpful in determining that i at least had the thing together correctly.
Seems a bit clumsy shifting, but it's not spinning and vibrating like it will be in use.
And that dang little spring on the linkage likes to pop off just looking at it! :butthead:
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Having the trans all sussed out gave me renewed confidence.
The crank went into Mom's freezer next to a big bag of blueberries..
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A couple of big 'murrican car-type sockets went into the toaster oven.
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I had always read about Yamabond or Hondabond or one of those,
Then which number and all that stuff started getting confusing.
So i used the old Flange Sealant.
When i build other motors, this is calling the big guns out.
So there you go. 518, Baby..
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Here's the right case half in the press.
A couple chunks of 4x4 are key.
What i didn't catch was setting a glowing-hot socket on the inner race of that main crank bearing.
(was busy with both hands for a while there).
When i set the frozen crank into the heated bearing, it just fell in.
NO press needed! :lol:
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The left case half had the other hot socket on it's inner race,
And i stabbed the trans gears in the right half real quick.
Might have been better to have them already in during crank press in hindsight..
It took a bit of pressing to the the left case to get it on.
The crank had likely warmed up a bit, but no big deal, went right together with a push.
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Again, wish i woulda gotten a pic of the press operation.
I used a big deep-well socket, that cleared the crank shaft, to push the left case on.

-One issue-
After i bolted the halves together, the crank was over to one side,
And didn't seem to spin very freely. Look closely at the above pic.

Hit it a few time with the rubber hammer, and it didn't help.
Panicked and called Jim, the master/guru,
And he told me to go ahead and give it some.
So i got out the BFH, and put the nut on to protect the shaft,
And gave it a good wack with the mini-sledge.
BAM! Perfect! Centered, and turns free as a butterfly... :boogie:
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Coming off that success, i had to go and put a few more things together.
OOoo, pretty.. A new JT sprocket, and a billet guard to cover it! :drool:
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Back when we got this bike, it had so many problems,
One of which was the kicker ratchet.
Feeling so ashamed for getting the POS, i dove blindly into buying NOS parts and kicker assemblies.
Got the kicker assembly replaced, but also bought more and a bunch of NOS parts.
Was convinced that the kicker ratchet must be a weak link or something..
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Spent a good amount of time adding the new pieces to the best of the used.
Making sure that everything is 100%..
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Bench is getting cleaner!
Next couple of assembly sessions should make for a good time.
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Re: '86 - Down the Rabbit Hole

Post by KDXGarage » 06:54 pm Mar 17 2019

Is that enough sealant? You have used that little before?
Thank you, Julien D for keeping the site going.

If you have a question about YOUR BIKE, please tell us what model YOUR BIKE is. :-)

Clatter
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Re: '86 - Down the Rabbit Hole

Post by Clatter » 07:24 pm Mar 17 2019

Yeah, it squeezes out in a little bead all around.
I put it on both sides for good measure.

Also violate the “don’t wipe it away” rule..
Can’t stand to see that little bloob all along the seam.
Doesn’t hurt to clean it up, if you do It right away,
And don’t use any solvent.
Right??

pkenney
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Re: '86 - Down the Rabbit Hole

Post by pkenney » 09:13 pm Mar 17 2019

Great work and thanks for the posts!
Its going to be one nice KDX.

Might be a little late but before you put the cylinder on its nice to clean up the castings a bit on the transfer ports, I semi knife-edged mine.

Any luck on the rear hub?
I found my old spare rear hub and its in worse shape than yours, someone tried to pry the bearings out and broke the side off.
Before I changed to the KX wheels I chucked the hub I was using in a lathe and cut the circlip groove a lit deeper which held up for one season.
I used a lathe but imagine if you were very careful with a dremel you might be able to accomplish the same thing.
I am slowly putting another 86 together so I need to hold onto it.

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Setback City

Post by Clatter » 11:03 am Mar 18 2019

Well, Sunday started out fun enough
(Jinxed myself, I did).

As the clutch-side cover came together a few surprises surfaced.
First of all, the '87-'88 use a bigger nut on the output shaft, coming into the clutch hub.
So I need to get one of those, and a washer that was missing from all three of my kicker ratchets..
This is just sitting here for decoration, and to keep things in order, I guess.
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Even better, the sight glass is loose and wobbly in it's hole; an oil leak waiting to start no doubt.
I noticed they sell them - anybody know the drill for installing a new one?
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Since the clutch cover assembly was a no-go, and you need to lock up the motor to install the stator,
I decided it was time to go ahead with the top end.

Uh, Oh.. :kick:
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Yes, that piston does indeed stick up pretty high.. :cry:

Turning it over assembled - "clunk" goes the piston.
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Time to start checking things..
First of all, the cylinder is indeed the same length as the old.
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Piston seems to check out.
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Crown height the same.
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Piston has a bit different ports and drillings, but that's just it being an aftermarket piston, right?
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So that leads to the rod.. *sigh*

Here's the one that came from a second, used ebay crank;
The crank that I sent to RB Racing for a rebuild.
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Here's the one that was running in the old lump.
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And, alas, here's the one in the 'new' motor.
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I'm guessing that my newbie mistake is missing the numbers on that rod?
Could it be that 1146 or 1069 are lengths?
How else can you tell if some a$$hole on ebay is suckering you?

Had some nasty thoughts at first; shaving down the piston crown,
Stacking cylinder base gaskets or making a spacer...

I'm buying another rod from Greg at Off Road Innovation,
And sending it along to Ron Black along with the crank from the lump.

Man, I hate ebay..
I hate ebay and everyone on it.



Set the motor finger-tight in the frame to get it all out of the way,
Then cleaned up and put away everything to do with this bike for a while.
Shore is purdy. Duh... :doh:
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Will attend to a few small things in the meantime,
Like sending in a shock spring for powder-coat.
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Or sussing out why my master cylinder kit doesn't seem right for some reason...
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But, it's going to be a while before anything meaningful happens here again. :sad:

And I am never ever buying anything on ebay again. Ever.

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Re: '86 - Down the Rabbit Hole

Post by KDXGarage » 11:52 am Mar 18 2019

WOW. I am sorry to hear of the issue! Take a break and come back at in the near future.
Thank you, Julien D for keeping the site going.

If you have a question about YOUR BIKE, please tell us what model YOUR BIKE is. :-)

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Re: '86 - Down the Rabbit Hole

Post by pkenney » 07:41 pm Mar 18 2019

Same thing happened to me on the rod.
I had Jeff Fredette do the crank and when I got it back it was about 0.100" too long.
He used a Hot Rods kit for the rebuild and reworked it for free but it was a pain to tear it down twice.
The old rod also had 6901 on it.

BTW, the old rod measured 5.465" from top to bottom.
Oh yeah, I drilled some holes in a 2X6 that the shafts dropped into that made reassembly much easier since the motor laid flat on one side.

[url=https://flic.kr/p/24CugHr]Image

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