KX Riders

Maintenance & Technical => KX250 / KX125 => Topic started by: Caddy 16v on September 15, 2010, 06:35:27 PM

Title: My 88/91 KX250 project
Post by: Caddy 16v on September 15, 2010, 06:35:27 PM: hi,

I got a free 88 and 91 KX250 given to me a while back, I'm in the process of rebuilding the 91 one first. So far I got the cylinder bored and got some parts ordered. I will be updating the pictures as I go. Next up is the frame and putting the engine back together. I'll let the KX500 swingarm on the 91 to see how it handles. So far it has been a great learning experience :-D

(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_295.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_299.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_300.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_502.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_501.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_514.jpg)
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on September 22, 2010, 03:57:09 PM: So I made some progress, assembled the engine, put some newer handlebars on it plus grips and levers, next up is painting the frame and fabricating the top engine mount plus the cooling system.

(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_536.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_550.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_560.jpg)
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on October 12, 2010, 07:41:08 PM: Got the frame painted, the engine assembled and put in for now, next is the cooling system when the parts arrive :-)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_692.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_590.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_587.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_699.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_701.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_700.jpg)
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on February 08, 2011, 09:21:39 AM: Made some progress:

Bolt kit:
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_929.jpg)

(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_951.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_961.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_958.jpg)

Still waiting one some parts to finish it so I can test the engine, also the plastics are really dull and worn by the sun, any tips on how to improve the looks? Will a heaadlight restore kit work?
Title: Re: My 88/91 KX250 project
Post by: 1989kawasaki on February 08, 2011, 09:52:19 AM: i bought the same bolt kit from motorsport fasteners for my 89 kx250
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on February 08, 2011, 05:34:17 PM: Yep its a good kit only the sub frame bolts are missing I think.
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on February 17, 2011, 09:13:59 AM: And some more progress:

(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_979.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_982.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_985.jpg)

Also cleaned the plastics with some magic eraser, they look much better now even though they are old. I'll need to use the heat gun on them some more:
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_984.jpg)

My doggy is helping:
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_959.jpg)
Title: Re: My 88/91 KX250 project
Post by: 1989kawasaki on February 17, 2011, 09:34:12 AM: you shoulda gotten the cylinder media blasted or whatever they do to it when they replate the cylinder. it makes it look brand new
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on February 17, 2011, 09:50:09 AM: I might soda blast it once I know its all running right, right now I just want to all make it work, after that it will be about looks :wink:
Title: Re: My 88/91 KX250 project
Post by: 1989kawasaki on February 17, 2011, 10:59:40 AM: Quote from: Caddy 16v on February 17, 2011, 09:50:09 AM
I might soda blast it once I know its all running right, right now I just want to all make it work, after that it will be about looks :wink:

i think you ought to . its all about looks for me
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 04, 2011, 03:13:50 PM: So, I had it all ready to go today for the first start up, wasn't fully assembled but enough to let it run and as I tried to start it my freaking kickstarter slips the whole time, sometimes it would engage a little bit, but it was no where enough to get the bike started :-( so now its all in pieces again and I'm trying to figure out what the problem with that ratchet is. How annoying, could have just been the cold weather but I never had problems like that with other bikes in winter... and what a waste of oil and coolant, I'll just get some ATF type F tomorrow... just had to vent a little bit :evil:
Title: Re: My 88/91 KX250 project
Post by: 1989kawasaki on March 04, 2011, 03:50:20 PM: change the ratchet spring
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 04, 2011, 04:41:30 PM: is the ratchet spring the big one at the end, or? I still have two others laying around so hope that will work.
Title: Re: My 88/91 KX250 project
Post by: 1989kawasaki on March 04, 2011, 04:43:35 PM: the big spring is the return spring. pull out the kick shaft and at the back of it there is a circlip and a small spring in there. go look then tell me if you found it.
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 04, 2011, 04:48:32 PM: Ok I found it on the parts diagramm, so can I just pull out the kick shaft or what? there is nothing holding it in place?
Title: Re: My 88/91 KX250 project
Post by: 1989kawasaki on March 04, 2011, 04:52:27 PM: you have to take the return spring out of the hole holding it on, then twist it so it clears the clutch basket, remove the return spring, turn the shaft counter clockwise , it should pull right out. then obviously remove the circlip holding the ratchet spring on then remove the spring. also check the condition of the ratchet teeth. will those instructions work for ya?
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 04, 2011, 04:55:37 PM: yes thanks that should work, will check it tomorrow!
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 05, 2011, 08:21:01 AM: YIEHHHAAAA my monster came alive muhahahahaaa, loud as hell without a muffler but I just couldn't resist trying to start it!! :-D

I switched the whole kickstart assembly with another one and it now works flawlessly, the teeth on the one in there were quite worn!

Now onto the rest of the bike, just need some more parts and it will be done.
Title: Re: My 88/91 KX250 project
Post by: 1989kawasaki on March 05, 2011, 11:16:05 AM: good im glad its fixed now, if it ever slips then it will be that spring.

which parts do you need?
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 05, 2011, 01:20:00 PM: To be able to ride it, I'll need a chain, muffler, the nut at the side of the swingarm bolt, rear brake pads and the bolt that holds the rear brake pedal.

Then to finish the bike it needs a rear fender, killswitch, front number plate, fork protectors and it needs the forks and shock rebuilt to let it loose on the motocross track.

Tomorrow I'll probably put evenything on that I can... it won't be pretty but that'll come later, all I want is something to ride right now.
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 06, 2011, 05:53:29 PM: So this is as far as I can go right now, to say that it is UGLY is an understatement :-( to get the engine running was the biggest priority! I'll get the rest of the parts and graphics kit as I go along and have money available.

(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_030.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_035.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_031.jpg)

Here is a pic of the worn ratchet:
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_029.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_028.jpg)
Title: Re: My 88/91 KX250 project
Post by: 1989kawasaki on March 06, 2011, 11:27:31 PM: youre right! UGLY is an understatement. you need a new: seat , side covers , rad shrouds.
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 07, 2011, 05:19:10 AM: But before that it'll get a silencer, chain, rebuilt rear master cylinder and some other nuts and bolts. Might just get a graphics kit later on instead of new plastics, that'll cover it up, the full plastics kit is not exactly cheap compared to the newer bikes.

I could call it a rat, looks abused but other than that fully functional, just imagine the looks on ppls faces when they get overtaken by it. :-D
Title: Re: My 88/91 KX250 project
Post by: Marco810 on March 12, 2011, 03:39:00 AM: haven't ever tried to touch up old plastics but i see theirs alot of methods/product floating around that seem to work. might be worth looking into
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 30, 2011, 09:21:48 AM: So I got a little update, got the silencer off a '92 and it fits, ordered a chain a while ago and the rear fender is also on they way plus some rear brake pads.

But there is one thing that concers me, I took the pipe off to put that copper gasket in and I could see a drip of anti freeze / coolant where the cylinder meets the pipe! :?

I searched around and the reasons I came up with are head gasket or the crank seals, or is it normal after a rebuilt? It barely has 10min of run time! I don't think it smokes like crazy, the only thing it did was leaking some oil goo onto the pipe which I thought was normal from not having that gasket in the pipe.

Any help/ suggestions? I don't want the engine to blow after I spent all that money on it :-(

Thanks, Bjoern
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on March 30, 2011, 05:36:40 PM: ...I ran it a bit more today and got the chain, so I was able to take it for a little ride, after that I took the pipe off again and there was no more coolant to be found inside, so I guess I got lucky. But it's running way too rich and doesn't really want to get on the pipe, so I'll have to play around with the jetting.
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on April 03, 2011, 01:17:05 PM: This is how it sits now, just waiting on the rear fender:
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_095.jpg)

And my dilemma with the missing throttle stop screw, hope that one won't take too long to show up, I bet when I get it, it will be raining for days on end :cry:
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_103.jpg)
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on April 13, 2011, 05:32:12 PM: Alright, finished it up tonight, I think I won't bother with a graphics kit at this point, maybe further down the road, now it's riding time! 8-)

(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_171.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMAGE_175.jpg)
Title: Re: My 88/91 KX250 project
Post by: Motorrad on April 13, 2011, 07:28:22 PM: Nice..

I think you need more stuff for your bench... I can see it in a few spots...
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on April 14, 2011, 04:54:13 AM: Hehe thanks, it's the shop of my "Grandpa in law" he had a logging company so I can't really start cleaning up in there, there is actually another work bench where the bike is pointing to. :-D
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on June 01, 2011, 06:19:18 PM: A couple updates, got a front number plate, the proper rear shock (race tech revalve) and some Cycra handguards, also had my forks rebuilt.

(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/DSCN0589-1.jpg)(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/DSCN0605.jpg)(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/DSCN0606.jpg)(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/DSCN0609.jpg)
Title: Re: My 88/91 KX250 project
Post by: Motorrad on June 02, 2011, 02:32:28 AM: Are the bars as bent as they look in that last picture??
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on June 02, 2011, 06:42:39 AM: The left side is bent, I was already considering to replace it, think I'll get a new one without the middle strut. Maybe a pro taper or something like that as long as it's not too expensive.
Title: Re: My 88/91 KX250 project
Post by: Motorrad on June 02, 2011, 06:52:07 AM: Quote from: Caddy 16v on June 02, 2011, 06:42:39 AM
The left side is bent, I was already considering to replace it, think I'll get a new one without the middle strut. Maybe a pro taper or something like that as long as it's not too expensive.

I have straightened bars worse than that... Large hammer. and a buddy to hold the front wheel :-D

Dont forget most protapers are bigger diameter on the mount.. so youll be buying those as well..
Title: Re: My 88/91 KX250 project
Post by: snoopjonnyjon on June 02, 2011, 07:49:44 AM: If you're on a tight budget, most shops have steel bars for $20-30. If you don't crash much, there's nothing wrong with them.
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on July 05, 2011, 08:30:11 AM: Hi,

so I have been riding it for a while and got over the fouling plugs problem but now something else buggs me.

Instead of having the 91 KX250 swingarm + linkage in there it appears to be out of a 91 KX500 and since I swapped the shock to the 91 KX250 one it's been sitting too low :?
Now for the real question: Anyone know if the linkages and length of the swingarm between the 250 and 500 are different? I measured the swingarm and linkage from my 88 KX250 and they apprear to be the exact same one, so did it change in 90-91 or is it still the same!?

With the KX500 shock in there it wasn't sitting low at all but I think the spring is a stiffer one, I could change that spring into the 250 shock but don't know if that would mess with the internals??

To add to the whole frustration is I adjusted the low speed compression clicker on that 250 shock and while I turned it all the way out some moisture formed around the screw and now the SUCKER won't turn in anymore from all the way out, so I'm riding around with fully soft compression :x

All that is really driving me up the walls, takes all the fun out, it just eats all my money, just wants more and more and more...

Sorry for the vent, any suggestions would be greatly apprechiated!

Bjoern
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on September 16, 2011, 06:54:29 AM: A little update, finally got the right swingarm and linkage, now it handles like it is supposed to. :-D Only waiting on my rear master cylinder rebuilt kit (of coarse they had to ship the wrong one) and I'm good to go again. My little mx track is starting to grow over from all the non riding... also made some fork guards out of pipe a while ago.

(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/DSCN1087.jpg)
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on May 07, 2013, 12:44:38 PM: ...has been awhile, added an oversized tank and wider footpegs:

(http://i593.photobucket.com/albums/tt13/caddy_16v/IMG_0531.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/IMG_0533.jpg)
Title: Re: My 88/91 KX250 project
Post by: motopunk on May 07, 2013, 05:53:56 PM: 250 and 500 swing arms are the same 87- 93 . the shock and linkage of 87-89 kx250 (=kx500 87-2004) is different to the 90-93 kx125/250 linkage. get the right one and the problem is gone. 8-)
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on May 12, 2013, 03:01:07 PM: I replaced the swingarm and linkage with the right one almost 2 years ago, so it's been great ever since! :-)
Title: Re: My 88/91 KX250 project
Post by: motopunk on May 12, 2013, 04:56:14 PM: ftp://
Quote from: Caddy 16v on May 12, 2013, 03:01:07 PM
I replaced the swingarm and linkage with the right one almost 2 years ago, so it's been great ever since! :-)

:-D... i´m glad to see pics of your finished bike...
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on September 24, 2015, 01:04:45 PM: After more than 2 years with no updates, here is how it sits now. New seat cover and a couple other things like improved upper engine mount and some new bearings. Just little things to make it more reliable.

(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMG_4195.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMG_4194.jpg)
(http://i593.photobucket.com/albums/tt13/caddy_16v/Motocross/IMG_4197.jpg)
Title: Re: My 88/91 KX250 project
Post by: SOHC on October 20, 2015, 08:46:12 AM: I like the green forks, how did you polish the plastics?
Title: Re: My 88/91 KX250 project
Post by: Caddy 16v on October 24, 2015, 06:18:39 AM: Initially I used Mr Clean magic eraser pads. Every now and then I clean the plastics with 303 Aerospace Protectant, leaves them really shiny!