KX250 rebuild - after all I've ridden it half a dozen times and it's worn out

[Arronduke]

Having never worked on a MX bike of any sort... I thought I would rebuild my new KX250. OK KX what is it and who makes it... and whats it do?... And now I own it because I need a dirt bike and all my friends have one.

Fat bald friend with too much cash... buys new designer dirt bike, even though he can't touch the ground... and sells the KX thats been in his shed for 4years and hes NEVER RIDEN... wanker..! So the offer is tooo good and I had to buy it.. wife slightly upset... no ideas why... serial whinger is that wife... Im thinking.! How long have I been maried....

Ok ok enogh is enough show me the dam bike.. what year is it... fu#king old heap of shit and I'm out of here . I hear...(again lol)

Bye...

KX250 1992... only dirt bike i have ridden in 20 yrs and about the 6th in history with a total off road hrs of about 2...



Can you tell i have not opened the new manual I just got from UK... I want to see if common sense can pull this apart without too many fu#k ups where you have to go back... so far so good.




Still no manual and now a few beers under the belt... feeling good... now I hope the wife does not want some help... I am in bike mode..



And yes if your still on board... Why TF am I doing rebuilding a 19yr old bike...(yes I'm am still working it out). and there is no way you will EVER get your money back. I have a few bikes and this is the most modern... on one side I just want to see how it works..everything is so new.. the other..mmm I like old things and this could be quite cool...now its old.

subframe all gone.. was trying for the engine on the floor tonight... beer can getting heavy.! need to piss.... (bugger some splashed on the wife's car)....:who cares:



What no... joining link, what sort of heap is this.. mental note.. add chain link for easy chain removal.

How the hell am I going to remove the chain...


Rear wheel out... yea man.. im sooooo cool..


right what's next.. that's right I tired... have to sit down to have an other beer... being 25 suxs.

Ok.. Im thinking

New crank - wiseco
New piston - wiseco
rad valves
fatty chamber
FMF rear exhaust... mental note... (not stinger)
13oz fly wheel weights for low down power for my marathsn Paris to Deker rides next sesson.

[cheese]

I'd only bother with go fast bits if you can get them really cheap. Just rebuild it and ride it. A bike that old will always be a money pit.

[CRF119]

How much did you pay for this museum piece? Not sure i would be using wiseco i no of some shop that refuse to install wiseco due to cold sizing issues.

Prox do OEM for a few companies so i use them and have been great.

Kawasaki to pretty cheap Crank and rod factory assembled packages.

[andy 101]

All of ya problems stem from what ya drink the 3rd photo mate, you drink lion red.

[cheese]

Say it like a french beer. lion (leeoon) rouge.
but yes its still pisse d'âne

[motor_mayhem]

As others have said I wouldn't go destroying the bank account for an old bike

Mxshop have a namura kit for $130 here:
http://www.mxshop.co.nz/parts-1/engi...250-92-04.html

But I would probably go with a wossner kit from motoxparts @ $180 and the top end gasket kit @ $50:

http://www.motocrossparts.co.nz/moto...e=1&piece=1236

They do crank kits as well:

http://www.motocrossparts.co.nz/moto...e=1&piece=1072

A new piston and gaskets should breathe a new life into your bike.

[unstuck]

The most cans of CRC i,ve ever seen. Farkin brilliant.

[White trash]

Outstanding thread, I love these old bike "do up" threads. If you'reother bikes are anything to go by, this will be one mint machine when done.

[Arronduke]

Thanks for the posts... $1500 for the heap..

I already have a wiseco piston and top end gasket set that came with the bike so thats the main reason for using a wiseco.

noticed it looks like it already has a boyesen reed or what looks like a boyesen reed valve.. could some one let me know what this is?

All help appriciated..





Yes Lion Red... mans beer... but I perfer Steiglarger Pure now thats a good drop.

[Arronduke]

motor mayhem.. thanks for the links.. I have no idea where to get dirt bike stuff.

New crank from motoXparts = $225 but wait.. they do re build kits and put them togeather for $160 bucks.. now that suits my budget.. sold.

rebuilt crank $160
Wiseco piston free.

Was going to go for a RAD valve as it was recommended but when I know what I have I will go from there.

New plastics would be nice... anyone have a clue where to get them?

Oh almost forgot found inside the reed valve... WTF so where is it from? Looks like a selector part but no idea.



haaa CRC great stuff I use lots of it on my bikes etc after washing them.

[barty5]

juat buy the rod kit there is a guy in west aucks who dose them for $60 which is where they send them anyway. ive got the number at work some where post tuesday.

[Taz]

Thats an interesting find in the reed valve. Was it on the carb side or engine side?

[Arronduke]

This bit was on the carb side... strange but i have not got any further so time will tell.

[Stylo]

motor mayhem.. thanks for the links.. I have no idea where to get dirt bike stuff.

New crank from motoXparts = $225 but wait.. they do re build kits and put them togeather for $160 bucks.. now that suits my budget.. sold.

rebuilt crank $160
Wiseco piston free.

Was going to go for a RAD valve as it was recommended but when I know what I have I will go from there.

New plastics would be nice... anyone have a clue where to get them?

Oh almost forgot found inside the reed valve... WTF so where is it from? Looks like a selector part but no idea.



haaa CRC great stuff I use lots of it on my bikes etc after washing them.

And I'm a WD40 man, you can actually clean your shoes with a couple of sprays each side and do all the other stuff, can't comment on the RAD valve thing as I'm on a KX5, should be pretty similar ?

[vr4king]

Looks like your in for a long one

I agree with the Lion Red comments they are never a good start to anything

I have rebuilt a 1996 kx250 a few years ago with no manual etc
Im gonna guees that is a RAD valve you have already........good luck finding reeds for it.
Those engines have what they call a KIPS power valve setup which a mission to sort out without the manual
As for the unknown part i bet youll find out what it is when you start to tear it down
Wiseco pistons are fine just give em time to warm up before you ring the tits of it

I wish I had the cash to do this sort of stuff for shits and giggles