2003 KX 250 SF Conversion

[umberto]

Yes, you do have to remold the tank to get clearance, but it's not too drastic.  I boiled water in a big soup pot and left the tank sitting in it for a few minutes.  This made the plastic soft but not too soft.  I pushed it up where I needed to, and then ran cold water over it it to set it. It worked very well and seemed to be very safe. 

I was not able to use the stock airboot, because the 500 carb is farther back than the 250 carb relative to the airbox location.  I have a 500 airboot that I am going to try to make work, but I haven't had a chance to try it yet. I've been riding too much lately, which is a good problem to have.   . I'll post updates as I get a chance.

[zz3gmc]

I used the 500 boot with an adaptor plate. The air boxs are slightly different between the 03 and 04 KX250s but Im pretty sure it will work.

[umberto]

I got all the plastic in for the bike yesterday.  I got 2008 KXF 450 shrouds, (they are larger than the 2008 KXF 250 shrouds), and they bolt right up without a lot of extensive modification.  When I did my original set on my 04 I read a post on thumpertalk, and that guy used 250 shrouds and modified the heck out of them. I read the article and did the same.  Come to find out the 450 shrouds are a lot simpler to fit.  Oh well, live and learn.   

[umberto]

So it turns out my coil was burned out.  I got some work done today, and was able to take her around the block for the first time.  The clutch is fried, and I have an oil leak around the clutch arm, but everything sounds good and works pretty well.

Thank you to Sandblaster for the troubleshooting guide (and for helping me save money on the coil).  I don't know if I would have been able to find the issue so quickly (and cheaply) without the guide.

Here's a video of me starting it this evening.  I still have work to do, but I'm getting much closer!

https://www.youtube.com/watch?v=UOHMTuQefYE&feature=youtu.be

[umberto]

I need some help with the clutch.  Will a 89 and up clutch fit an 88, or is it a one year wonder like the cylinder?  The part numbers are different on the OEM fiche, and Rocky Mountain lists clutches for 89 and up, but not 88.  I can buy an 88 clutch on eBay, but the selection is limited and they are pretty pricey.  I realize I probably need a really good clutch for that much power, but I don't want to overspend on a bike that is not going to be raced.  Thank you for the help!

[sandblaster]

The kx500 basket and pressure plate are the same according to my info....

[mixn-gas]

looks and sounds good on the video,
am interested on how you do your intake boot, if you can post pics up on here when you build it that would be helpful!
-logan

[umberto]

The kx500 basket and pressure plate are the same according to my info....

I got a clutch ordered from Rocky Mountain.  Last night I remembered the list you posted on your web site that shows the different parts that fit different years.  That's such an awesome reference tool, thank you for sharing it with us.

http://oem-cycle.com/KAWASAKIKX500BIKEID.shtml

[umberto]

looks and sounds good on the video,
am interested on how you do your intake boot, if you can post pics up on here when you build it that would be helpful!
-logan

The air box boot is giving me fits right now.  I am using a 96 K5 boot, but it is really squished if you do a solid plate across the airbox to mount it (it pushes into the top of the shock, but not the spring).  I am trying to think my way around it, but not having much luck yet.  Maybe zz3gmc can post some pics of his airbox.

[zz3gmc]

It so happens that I will be doing a top end rebuild soon. I will try to take some pics.

[motopunk]

umberto, why not using the 2003 oem-250 boot?  ...  on my 93 it had worked very well ...

[umberto]

umberto, why not using the 2003 oem-250 boot?  ...  on my 93 it had worked very well ...

I did try it, but it seemed to be even further back than the k5 boot.  I'll give it another try just to make sure.

[zz3gmc]

I may have figured out your problem umberto. There were a few changes to the intake tract between the 03 and 04 KX250s. The airbox, airbox boot and intake manifold are different between the 2 years. The 03 airbox to airboot mounting flange is flat(airbox side) and on the 04 the airbox to airboot flange is recessed about a 1/2" or so. This is probably why the airboot is squashed using the 03 airbox. I think if you go with a 04 KX250 airbox and the 500 boot with a adapter plate you should be good to go.

[zz3gmc]

I will try to get a pic tonight of the 2 airboxes. I have both.
 

[umberto]

I'm glad you thought of that, I was about to do major surgery.