KX Riders

Maintenance & Technical => KX500 Original => Topic started by: Jeff90lx on November 07, 2016, 06:55:00 AM

Title: 93 KX 500 Rebuild
Post by: Jeff90lx on November 07, 2016, 06:55:00 AM
Hey Guys!

  So, I'm new to the two stroke world. But I bought a 93 Kx500 a couple months ago and it has been a blast to ride until about 2 weeks ago when it died on me and I couldn't get it started. Anyway after doing some troubleshooting it had about 50 PSI of compression. Not good. So I tore the top end apart and the piston looks terrible. I will take some pictures tonight when I get home but I was wanting to get some opinions on who I should send the cylinder to? I want to get it re-plated and get the intake and exhaust ports reworked (Sharpened) and get the KIPS valve cleaned and reworked also. I'm looking to go with a Wiseco Piston kit. Any advice is appreciated... Thanks Jeff 

Title: Re: 93 KX 500 Rebuild
Post by: Foxx4Beaver on November 07, 2016, 07:11:59 AM
welcome to the site Jeff.

1st, scratch the idea of Wiseco!....go with a Wossner.
Either PowerSealUSA, or Millenium Tech are the best places to have your jug plated.
Our member Sandblaster may be able to rework the ports.
Title: Re: 93 KX 500 Rebuild
Post by: Jeff90lx on November 07, 2016, 01:03:00 PM
(http://i17.photobucket.com/albums/b70/jeff90lx/Mobile%20Uploads/IMG_1262.jpg) (http://s17.photobucket.com/user/jeff90lx/media/Mobile%20Uploads/IMG_1262.jpg.html)
(http://i17.photobucket.com/albums/b70/jeff90lx/Mobile%20Uploads/IMG_1266.jpg) (http://s17.photobucket.com/user/jeff90lx/media/Mobile%20Uploads/IMG_1266.jpg.html)
(http://i17.photobucket.com/albums/b70/jeff90lx/Mobile%20Uploads/IMG_1264.jpg) (http://s17.photobucket.com/user/jeff90lx/media/Mobile%20Uploads/IMG_1264.jpg.html)(http://i17.photobucket.com/albums/b70/jeff90lx/Mobile%20Uploads/IMG_1265.jpg) (http://s17.photobucket.com/user/jeff90lx/media/Mobile%20Uploads/IMG_1265.jpg.html)

Title: Re: 93 KX 500 Rebuild
Post by: Jeff90lx on November 07, 2016, 01:04:59 PM
Has some deep gouging near the exhaust ports, any ideas on what went wrong? Any piston experts out there?
Title: Re: 93 KX 500 Rebuild
Post by: b4himdude on November 08, 2016, 01:22:28 PM
Take foxx's word on the Wiseco. For some reason the wrist pin bearing loves to disintegrate. Happened to me and another few members. Go with wossner. I've had good luck with plain old pro X but I inspect the cylinder frequently as well
Title: Re: 93 KX 500 Rebuild
Post by: Jeff90lx on November 09, 2016, 02:41:23 AM
Thanks for the input guys,

 I found a piston guide but I can't get the thing to load for some reason... I just don't want to put this thing back together if the issue that caused it is not resolved. I will be sending the cylinder to Millennium Tech. to get re-plated and will probably go with the Wossner piston as suggested. The few people I have talked to about it say that it looks like some kind of lean condition that caused it, however from what I've read... If the bike had an air leak it would have been running funny prior to giving up the ghost. It's just weird because the bike ran great right up to the end... So I'm a little stumped  :?
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on November 09, 2016, 03:01:54 AM
Do yourself a huge favor and check the crank for wear between the rod and the crank halves.
Get a feeler gauge and stick it in there as shown below:

(http://www.oem-cycle.com/forum/download/file.php?id=3371)

.016" -.020" is factory new specs.
You can run the crankshaft all the way to .028" before it's reached it's service limit.
If it's out of service specs it's time for a full rebuild.

If it is good you could install the new top end.
However, if you choose to only replace the top end, either do a leak down test yourself or have a shop do it to determine your seal condition. If it won't pass a leak down test then you know it's time to replace every seal or you risk burning up your new top end.

If I were you I would disassemble the rest of the engine and at a minimum replace every, bearing, washer, snap ring, bushing, seal, and gasket possible. I would also carefully inspect the shift forks, drum, and gear dogs.
Why? Without knowing the true history of that engine and no leak down test done before it was disassembled, you have no idea what you have. You could drop some serious coin into the top end and then fry it shortly thereafter.

We have heard too many stories of guys getting frustrated and selling their K5's for scrap because they did not understand the risks of not checking a few things...
Title: Re: 93 KX 500 Rebuild
Post by: Jeff90lx on November 09, 2016, 04:44:18 AM
Sandblaster,

It looks like you are in Oregon. I'm up in Washington, are there any local K5 guru's I could take it to for a full rebuild?
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on November 09, 2016, 07:04:06 AM
I don't know any in Washington off the top of my head.
I'm about 2 hours south of the Washington/Oregon border in Eugene.
Some others on this site may know of someone closer..
Title: Re: 93 KX 500 Rebuild
Post by: jethrobolas on November 11, 2016, 10:33:50 PM
Ha! Bought a running but clapped 93 couple years ago. Rode it twice and tore it dkwn. One ride was the purchase test. Accumulated goodies for a year.
Finished it up this spring. New tire, new wossner purchased from powerseal with replate, mains with seals, squish and compression release by Larry Wiechman, gasket and seal kit, chain and sprockets, couple trans bearings, clean and grease all chassis bearings, fresh brake juice, throttle cable, and blahblah.
Fired it up. Rolled my track cautiously. Around the track again with a bit more gusto. Open it up to run the front yard trail. Found air near my driveway on the k5 that no other bike could ever find...then skidded into a stack of a dozen utility poles laying in my yard. Hard.
Out of work for 6 weeks. Fractured tibial plateau (lucky that was all.....3 cartwheels before MY first bounce according to several of my sons buddies). New handlebars. New grips. Little tweakin' on the subframe. Sat until this October when I posted it on cl (plenty other toys).

Finally, after 4 or 5 years of talking about it, took my son to badlands ohv area and I chose the k5. Stock but fresh everything. He took my kdx200 of the same vintage. We had a blast! The k5 is no longer listed!



https://youtu.be/d0nVPqWhb28

Went from a 60 pilot to a 55. Blubbering like crazy. Video is with a 52, stock needle, clip all the way at the top. Still feels rich at small throttle and idle. Feel like i checked float level already, but winter is here and I do have a nice place to wrench on it during winter.....

Threadjack over.


Powerseal did find cracks in my transfers (I think, or maybe exhaust) but money cures almost anything.

With the proper tools, a manual, a bit of mechanical aptitude and this forum you could probably get it up to snuff with a minimum of outsourced work. Just sayin....
Title: Re: 93 KX 500 Rebuild
Post by: Jeff90lx on November 28, 2016, 03:55:35 PM
Well, I finally got around to taking measurements... I can fit .030 on both sides of the rod pretty easily... must be time to do the whole thing. Anyone have recommendations on full motor rebuilds? The closer the better... I'm in Washington. I could probably handle it, I would just prefer it gone through by an expert.
Title: Re: 93 KX 500 Rebuild
Post by: Jeff90lx on November 29, 2016, 04:01:39 AM
Well, I finally got around to taking measurements... I can fit .030 on both sides of the rod pretty easily... must be time to do the whole thing. Anyone have recommendations on full motor rebuilds? The closer the better... I'm in Washington. I could probably handle it, I would just prefer it gone through by an expert.

Also forgot to mention I found some cracks along the intake bridges... So maybe that's why she decided to let go... Now more than ever, I think I want to send this to somebody to go through it and fix any other outstanding issues. Sandblaster, are you looking for more work? Does anybody else have any recommendations for good thorough KX500 engine builders?
Title: Re: 93 KX 500 Rebuild
Post by: umberto on November 29, 2016, 04:06:31 AM
I would definitely send a PM to Sandblaster.  Your motor will come back looking and running better than new.
Title: Re: 93 KX 500 Rebuild
Post by: 1FAST450R on December 01, 2016, 02:11:29 AM
i used PowersealUSA and couldn't be happier. Definitely use the Wossner.
Title: Re: 93 KX 500 Rebuild
Post by: AfricaOffroad on December 23, 2016, 04:50:43 PM
Not sure if it's the picture, but piston looks like it has major damage on its crown from detonation.
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on December 24, 2016, 02:09:51 AM
I would definitely send a PM to Sandblaster.  Your motor will come back looking and running better than new.

We do like to get them clean inside and out...

(http://www.oem-cycle.com/forum/download/file.php?id=4782)

(http://www.oem-cycle.com/forum/download/file.php?id=4783)
Title: Re: 93 KX 500 Rebuild
Post by: Jeff90lx on January 04, 2017, 04:36:10 PM
I will be getting ahold of you in the next couple days, I just need to figure out how I'm gunna get it down there... Nice work BTW...
Title: Re: 93 KX 500 Rebuild
Post by: Jeff90lx on February 21, 2017, 07:16:06 AM
I would definitely send a PM to Sandblaster.  Your motor will come back looking and running better than new.

We do like to get them clean inside and out...

(http://www.oem-cycle.com/forum/download/file.php?id=4782)

(http://www.oem-cycle.com/forum/download/file.php?id=4783)

Finally, got off my dead AZZ and got the bike dropped off with Mike and Jason... I'm chomping at the bit to see what kind of good work these guys can do for me... Mike would you mind updating this thread along the way?
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on February 21, 2017, 08:28:04 AM
Sure thing...
It may be a bit because my website which I host the pics on is having tech difficulties since the last update was done.
It's being worked on :-)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 01, 2017, 04:36:17 PM
Jeff's 93 KX500 build... Jason has his work cut out for him on this build...

(https://scontent.fslc2-1.fna.fbcdn.net/v/t1.0-0/s261x260/17021766_1366841716695604_4180879663563306264_n.jpg?oh=d165857d11910388d3e6bcb686078238&oe=5941A0B0)

Didn't take long  8-)

(https://scontent.fslc2-1.fna.fbcdn.net/v/t31.0-8/17097766_1366841843362258_5408461800969763565_o.jpg?oh=2568f64be18b11ef41cb355b3de84c5a&oe=593B0306)

Nothing like having a customer help you  :lol:

(https://scontent.fslc2-1.fna.fbcdn.net/v/t1.0-9/17021846_1366842303362212_6520242571902095265_n.jpg?oh=6fd6d4b545d171e6bce782f9eba4dc23&oe=5931D939)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 01, 2017, 04:37:45 PM
Yeah, this crank is done... but wait until Jason puts a little effort into it..

(https://scontent.fslc2-1.fna.fbcdn.net/v/t1.0-9/17098459_1366843270028782_7253118094027813921_n.jpg?oh=884209e2094b364302b3a2866ce3fc62&oe=596D7856)

A little welding will go a long way.

(https://scontent.fslc2-1.fna.fbcdn.net/v/t1.0-9/17021571_1366844023362040_8572621740719450395_n.jpg?oh=8b931518204b84f96d556e40425ae571&oe=592E9418)

 Same damage, different view..

(https://scontent.fslc2-1.fna.fbcdn.net/v/t1.0-0/s261x260/17021711_1366844420028667_5228112937119173660_n.jpg?oh=084dbc1d5b6f48647a0d67a413043153&oe=593FFBAA)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 01, 2017, 04:38:58 PM
There is a lot of clean up in Jason's builds...

(https://scontent.fslc2-1.fna.fbcdn.net/v/t31.0-8/17038479_1366844593361983_8749496996846745872_o.jpg?oh=c376919c891e27c791e1a10c31ca3c6a&oe=593D911F)

 This is the case and clutch cover after the bearings, seals, gaskets, and sealant, have been removed. They are clean and prepped for weld..

(https://scontent.fslc2-1.fna.fbcdn.net/v/t31.0-8/16992407_1366845063361936_7606536479334451136_o.jpg?oh=32b492a6ac6e18297d3720b6892ec4e1&oe=596F5327)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 05, 2017, 02:49:36 AM
It was hard to see but the other case was cracked as well... No biggie... Jason will get it fixed up good as new..
Title: Re: 93 KX 500 Rebuild
Post by: Jeff90lx on March 08, 2017, 03:34:26 AM
Jeff's 93 KX500 build... Jason has his work cut out for him on this build...

(https://scontent.fslc2-1.fna.fbcdn.net/v/t1.0-0/s261x260/17021766_1366841716695604_4180879663563306264_n.jpg?oh=d165857d11910388d3e6bcb686078238&oe=5941A0B0)

Didn't take long  8-)

(https://scontent.fslc2-1.fna.fbcdn.net/v/t31.0-8/17097766_1366841843362258_5408461800969763565_o.jpg?oh=2568f64be18b11ef41cb355b3de84c5a&oe=593B0306)


For the record, I had a wrench in my pocket and was digging for it  :-D

Nothing like having a customer help you  :lol:

(https://scontent.fslc2-1.fna.fbcdn.net/v/t1.0-9/17021846_1366842303362212_6520242571902095265_n.jpg?oh=6fd6d4b545d171e6bce782f9eba4dc23&oe=5931D939)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 08, 2017, 08:45:03 AM
lol...
I just got a call from the local dealer and about 90% of your build parts came in so we are getting closer.
Jason won't be in today but he said that he will be in Thurs or Fri to start the port work on your cylinder  8-)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 09, 2017, 11:00:07 AM
I know it's a minor part but the shift lever came in today... 20mm longer then stock...
Of course we had to change out the shift shaft to the 94-04 so that the splines would fit but I think it is well worth the upgrade.
I like mine..  :lol:

(http://www.oem-cycle.com/forum/download/file.php?id=5047)
Title: Re: 93 KX 500 Rebuild
Post by: KXDINO on March 09, 2017, 11:24:19 AM
does it have a part number for that piece blaster.
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 09, 2017, 12:57:59 PM
It should be 01-0347-10-30
But regardless, you order a KX450F 06-15 shift lever and it will fit... But that extra 20mm of length is great.
Title: Re: 93 KX 500 Rebuild
Post by: reklessj on March 09, 2017, 02:58:56 PM
I know it's a minor part but the shift lever came in today... 20mm longer then stock...
Of course we had to change out the shift shaft to the 94-04 so that the splines would fit but I think it is well worth the upgrade.
I like mine..  :lol:

(http://www.oem-cycle.com/forum/download/file.php?id=5047)
Got my +20mm for x-mas and yet to put it on. Got to get to one of these days
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 09, 2017, 03:22:05 PM
When I first put mine on it was the first time I didn't have to contort my boot to shift gears..
Title: Re: 93 KX 500 Rebuild
Post by: KXDINO on March 10, 2017, 08:30:53 AM
Thanks blaster.
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 13, 2017, 12:44:55 PM
Jason is hard at it... Porting takes forever!!!

(http://www.oem-cycle.com/forum/download/file.php?id=5053)

(http://www.oem-cycle.com/forum/download/file.php?id=5054)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 14, 2017, 02:04:26 PM
Still hard at it... Same cylinder, different day...

(http://www.oem-cycle.com/forum/download/file.php?id=5056)

(http://www.oem-cycle.com/forum/download/file.php?id=5057)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on March 17, 2017, 08:10:03 AM
After doing the base porting, Jason is Vapor Blasting the cylinder to clean it up.
Once it is done it will get all final port work then it will go off to plating.
Once it comes back, it will get the final Vapor Blasting and then polishing, clean up, then assembly..
Still a lot of work to do..

(http://www.oem-cycle.com/forum/download/file.php?id=5059)

I don't think most people fully grasp how much work Jason's level of porting takes.
Here is a bit of a secret.
In the first hour to hour and a half you can get 80-85% of the basic port work done, or something comparable to E. Gore, or some of the other big name shops. To get that last 15-20% takes more and more time.... But if your looking for a quality port job you won't see much if any better then Jason's work any where...
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on April 06, 2017, 11:05:41 AM
It's like pulling teeth to get the Wossner Pistons and Rod kits....
I guess I should not have told so many people how good they are  :|

I finally tapped all the holes for the 2 piece clutch cover..

(http://www.oem-cycle.com/forum/download/file.php?id=5104)

It's gonna look great.

(http://www.oem-cycle.com/forum/download/file.php?id=5105)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on April 06, 2017, 12:34:29 PM
I do have a few more to finish...

(https://scontent.fslc2-1.fna.fbcdn.net/v/t1.0-9/17796667_1403477996365309_3435786266291803790_n.jpg?oh=b758cfd0b055aada3cdd49db18e37a06&oe=59942F64)
Title: Re: 93 KX 500 Rebuild
Post by: umberto on April 06, 2017, 01:16:02 PM
Any of those for sale?
Title: Re: 93 KX 500 Rebuild
Post by: reklessj on April 06, 2017, 03:08:11 PM
Any of those for sale?

+1
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on April 18, 2017, 07:35:44 AM
We finally received a Wossner rod  :-o
I couldn't get the one's I ordered from Wossner as they are on back order (Forever), but I did find one in the UK.
It only cost me double what it should have but you gotta do what you gotta do.
I want this engine D.O.N.E...

(http://www.oem-cycle.com/forum/download/file.php?id=5140)

But that's not good enough...

(http://www.oem-cycle.com/forum/download/file.php?id=5141)

That's better...
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 27, 2017, 11:12:23 AM
Delay delays delays delays... But finally.... Finally making some progress..
And guys.... delays will only get worse until we are making all the part ourselves  :cry:


(http://www.oem-cycle.com/forum/download/file.php?id=5823)


I love the color of this cover...


(http://www.oem-cycle.com/forum/download/file.php?id=5824)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 27, 2017, 11:13:23 AM
It's gonna run good and look great!
Titanium color cover with titanium bolts  :-o


(http://www.oem-cycle.com/forum/download/file.php?id=5825)


(http://www.oem-cycle.com/forum/download/file.php?id=5826)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 27, 2017, 11:14:05 AM
(http://www.oem-cycle.com/forum/download/file.php?id=5827)


Now for the good part...


(http://www.oem-cycle.com/forum/download/file.php?id=5828)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 27, 2017, 02:56:22 PM
You put all the blood, sweat, and tears, into building a awesome engine.
Why not spend a few minutes (Ok, maybe a little longer) cleaning out the carb?


(http://www.oem-cycle.com/forum/download/file.php?id=5829)
Title: Re: 93 KX 500 Rebuild
Post by: umberto on May 28, 2017, 02:08:54 AM
That motor looks cleaner than a new bike.  You and Jason's work has started looking more and more like dirt bike porn.   :-D
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 28, 2017, 03:58:46 AM
This build is all Jason.
I'm just posting his great work for him as I am a little better on the PC  8-)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 28, 2017, 03:39:35 PM
When you are installing a engine after a rebuild there is so much that needs to be done..

(http://www.oem-cycle.com/forum/download/file.php?id=5830)

Thoroughly clean the carb.
Install a new throttle cable.
Completely disassemble, clean, and re-seal the air box boot, and so much more.
Then you find all the small things the bike needed.
In this case, exhaust mounts, muffler seal, and several misc doodads..

(http://www.oem-cycle.com/forum/download/file.php?id=5831)

(http://www.oem-cycle.com/forum/download/file.php?id=5832)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 28, 2017, 03:40:31 PM
(http://www.oem-cycle.com/forum/download/file.php?id=5833)

(http://www.oem-cycle.com/forum/download/file.php?id=5834)

(http://www.oem-cycle.com/forum/download/file.php?id=5835)

(http://www.oem-cycle.com/forum/download/file.php?id=5836)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 30, 2017, 01:47:30 PM
New engine... First kick start up...


https://www.youtube.com/watch?v=CdxsGnkWbYY (https://www.youtube.com/watch?v=CdxsGnkWbYY)


Another nice job..
A little of this and that..

(http://www.oem-cycle.com/forum/download/file.php?id=5837)

(http://www.oem-cycle.com/forum/download/file.php?id=5838)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 30, 2017, 01:48:23 PM
Love this stuff..

(http://www.oem-cycle.com/forum/download/file.php?id=5839)
Title: Re: 93 KX 500 Rebuild
Post by: sandblaster on May 30, 2017, 01:48:47 PM
First heat cycle..


https://www.youtube.com/watch?v=L7BFr5K70ls (https://www.youtube.com/watch?v=L7BFr5K70ls)