Motor years that will work with ea. other

[Sharky74]

Just curious if a 1990 motor will work in a 99 frame? My 99 needs a crank and have a lead on a 90 that runs. Will it work easy enough? Comes complete except maybe minus the carb and Cdi /coil

[Pmcg]

89-04 should all bolt in with no issues. There was a change in the electrical system in 92 I think but if you're going to use your old electric there should be no issues.

[Sharky74]

That is what I was thinking, thanks for the clarification.

[motopunk]

the engines before ´92 have the shorter stroke.
 by using the newer ignition (in case of right fitment of the statorplate in the also shorter ignition housing) ,you have to install it at the later timing mark. than follows maybe a little bit jetting and all will work properly... 


older engines ´85-88 use the 8mm motor-bolts. ´85-91 the 15mm swingarm-bolt . in 89 came the 10mm motormounts and in 92 came the 17mm swingarm bolt . if you drill the engine-mounts to the right size , will all older kx250 engines fit to the newer frames. position of the lower engine mounts has never changed. its possible that you need some handmade brackets for the headstay ... 

watch out that you also need the older swingarm of 92-93 , because in 94 and newer were the engine smaller on the rear and the swingarm became the bigger and longer bearings... 

its makeable, but a little bit easier to bring a newer engine to an older frame.

[dave916]

the engines before ´92 have the shorter stroke.
 by using the newer ignition (in case of right fitment of the statorplate in the also shorter ignition housing) ,you have to install it at the later timing mark. than follows maybe a little bit jetting and all will work properly... 


older engines ´85-88 use the 8mm motor-bolts. ´85-91 the 15mm swingarm-bolt . in 89 came the 10mm motormounts and in 92 came the 17mm swingarm bolt . if you drill the engine-mounts to the right size , will all older kx250 engines fit to the newer frames. position of the lower engine mounts has never changed. its possible that you need some handmade brackets for the headstay ... 

watch out that you also need the older swingarm of 92-93 , because in 94 and newer were the engine smaller on the rear and the swingarm became the bigger and longer bearings... 

its makeable, but a little bit easier to bring a newer engine to an older frame.

what bike are we talking about,500 or 250

[motopunk]

oh i was on the 250-way... 
but some of the steps will be the same by the k5-engine swap .

in case of the k5-engines it is much easier as on the 250´s there is only to watch out for the headstay-brackets and the smaller engine bolts ´85-88.
 by making bushings or drilling bigger holes,like its needed,  could all engines be swapped ´85-2004 ...newer pipes, ignition and carbs will also work well on the older engines before 89...

[Sharky74]

Well I have a 90 kx 500 engine coming. No carb, Cdi or coil with it and my stator is junk in my 99 motor and it ( the 90 motor) will be going into the 99 frame.
Will I need to get a 1990 Cdi to make it work? And can still use the 99 coil? Or a 99 stator and use my existing coil and Cdi?

Are the cases the same for mounting purposes? Will I need to rejet my 99 carb?
Still looking for a 99 stator if one is out there. The 94 I had a lead on looked different? Will it work with a 99?

Sorry for so many questions, I just want it to run. In the process of rebuilding my 99 but that may be a while out and still need the stator for it.

Thanks

[sandblaster]

I have collected a lot of interchange info here:
http://www.oem-cycle.com/KAWASAKIKX500BIKEID.shtml
CDI FITS 89-04 KX500 – 21119-1267 So this will work with any combo of stator or coil from 89-04
COIL F6T536 FITS 83-04 KX500 - 21121-1186 So this will work with any combo of CDI or stator from 89-04
Stator (2 coil style) FITS 87-89 KX500 - 21003-1169
Stator FITS 90-91 KX500 Works with 90-91 fly wheel only due to it's small size.
Stator FITS 92-04 KX500
Cases are the same.
Carb rejetted? If everything else is equal, probably not.
What is your altitude, current jetting, needle, and needle position?

[motopunk]

Well I have a 90 kx 500 engine coming. No carb, Cdi or coil with it and my stator is junk in my 99 motor and it ( the 90 motor) will be going into the 99 frame.
Will I need to get a 1990 Cdi to make it work? And can still use the 99 coil? Or a 99 stator and use my existing coil and Cdi?

Are the cases the same for mounting purposes? Will I need to rejet my 99 carb?
Still looking for a 99 stator if one is out there. The 94 I had a lead on looked different? Will it work with a 99?

Sorry for so many questions, I just want it to run. In the process of rebuilding my 99 but that may be a while out and still need the stator for it.

Thanks

in ´92 came the crank with more weight, that gives a little bit more torque...
  the rest of the engines ´89-2004 is 100% identical and all parts interchangeable ...
  you can install the ´90-kx500 engine, like the ´99 engine was installed in the frame. same ignition and jetting..  it will work properly...

[sandblaster]

Except....   
The shift shaft and lever which use a larger diameter spline starting in 94..
You can put any year of shift shaft and lever on the 89-04 engine, you just need to use the matching spline...
89-91 flywheel and stators are tricky depending on the size and amount of coils...
You can use any years from 89-94 as long as you have the matching flywheel...

[motopunk]

Except....   
The shift shaft and lever which use a larger diameter spline starting in 94..
You can put any year of shift shaft and lever on the 89-04 engine, you just need to use the matching spline...
89-91 flywheel and stators are tricky depending on the size and amount of coils...
You can use any years from 89-94 as long as you have the matching flywheel...

the man of steele has spoken... 
full agreed... 
 the new shift-shaft with bigger diameter splines came in 94 to all kx-bikes 125-500...
new shift levers ´83 and up are still available in aftermarket ...

[sandblaster]

I get lucky sometimes