89 K5 w/ 02 KX 250 front end

[emullen]

Heard that a 2002 or older KX 250 front end will directly bolt up to a 87 and  89 k5 can anyone verify this?
Are the 125 fronts the same as the 250 and then how about the RM  250/125?
Thanks

[doordie]

No,you have to change "steeringaxel" at topclamp.

[emullen]

steeringaxle-  ia that the stem?  are you saying that I have to press the stock stem into the kx 250 tripple?  Do you know of any upside down newer forks from any bike that might bolt up?  thanks

[don46]

I have done this on newer k5 bikes, as I recall the steering stem on the 88-89 bikes is to small on the bottom where it presses into the clamp. I ordered a newer stem from emig racing. If I were going to all the trouble I would try to get a set of 05-06 kx250 forks or at least a set of 04kx250f forks. A couple of years ago I picked up a brand new set of 250f forks on ebay for $250, and recently got forks and shock for $110. I'm sure there will be some response that the k5 forks are as good as the 250 forks, but, having raced 125, 250f and 250 for many years, I can tell you the newer stuff is much more advanced. If all you want to do is trail ride then maybe the older stuff is OK, for my money I try to go with the latest stuff. I have 2 k5's in 02 kx 250 chassis and 1 in a 04 250f chassis (work in progress) 2 have the o4 250f forks and 1 has the 02 250 forks they both work good. 1 other point the 99-01 125 and 250 forks are the same, they have different valving and springs. the 02 forks are larger diameter so iff you change make sure you use the forks and triple clamps from the same year.   Good luck.

[emullen]

please let me know about your 250f I have one that I planned on doing but the downtube is right were the exhaust port are you cutting this

[doordie]

You make a sleeve to older stem and then insert it to new clamp and use a bolt and loctite to secure it.

Have done it,works well even when you jump as "Bubba"!   

[don46]

I did cut the down tube, and replaced it with the downtube from an old k5 frame, it came out really well but the whole job was more work than I anticipated. The kx250 chassis is much easier to retrofit a 500 motor, the 250f chassis requires modification to the airbox, the right side of the frame to allow the clutch cover to be removed, and many small mods. it was a real pain in the you know what. The 250f air boot is to restictive and small, you have to install a 250 filter system and cut part of the airbox, I fabricated a piece of aluminum to allow the 250 filter to fit. Anyway good luck, if you would like to see pictures let me know an I'll get you some