Author Topic: Project Clapped out 1998 KX250... what works?  (Read 16323 times)

0 Members and 3 Guests are viewing this topic.

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Project Clapped out 1998 KX250... what works?
« on: February 12, 2018, 11:40:03 AM »
Jason has had this bike kicking around for a lot of years...
In 1998 this was the bike of the year.
It is well worn and the top end is completely clapped out.
I've always focused on the KX500's but we are going to see what we can do on this KX250...
Before we do anything it is getting the air cleaner cleaned up, fresh fuel and oil, new plug, and a street tire on it.
Then it is headed to the dyno so we can have a good laugh at it..

The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline DoldGuy

  • Hero Member
  • *****
  • Posts: 1,198
Re: Project Clapped out 1998 KX250... what works?
« Reply #1 on: February 12, 2018, 02:51:31 PM »
38.8 RWHP @ 8200 RPM.....What’s your guesstimate? Goals?
Its Never too Late to Have a Happy Childhood!

Offline umberto

  • Administrator
  • Hero Member
  • *****
  • Posts: 2,488
  • First Ride 02-02-19
Re: Project Clapped out 1998 KX250... what works?
« Reply #2 on: February 12, 2018, 03:16:35 PM »
Is that something over the rear shock reservoir, or is that an Ohlins shock?
Perhaps I have a dirt bike addiction?

03 KX 250/88 KX 525/2017 KX250F - Goliath
17 KX250F/04 KX250
04 KX 250 - Lunchbox's Bike
05 KX 125/144

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Re: Project Clapped out 1998 KX250... what works?
« Reply #3 on: February 12, 2018, 04:31:05 PM »
38.8 RWHP @ 8200 RPM.....What’s your guesstimate? Goals?

I have no guesses or specific power goals other then more...
And, I will be keeping in mind a conversation we had a few years back  8-)
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Re: Project Clapped out 1998 KX250... what works?
« Reply #4 on: February 12, 2018, 04:31:25 PM »
Is that something over the rear shock reservoir, or is that an Ohlins shock?

Ohlins  :-o
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline umberto

  • Administrator
  • Hero Member
  • *****
  • Posts: 2,488
  • First Ride 02-02-19
Re: Project Clapped out 1998 KX250... what works?
« Reply #5 on: February 13, 2018, 12:29:12 AM »
It looks like it has aftermarket clamps too and at least one excel rim. Somebody must have loved it at one time. Do you guys know much about the bike?
Perhaps I have a dirt bike addiction?

03 KX 250/88 KX 525/2017 KX250F - Goliath
17 KX250F/04 KX250
04 KX 250 - Lunchbox's Bike
05 KX 125/144

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Re: Project Clapped out 1998 KX250... what works?
« Reply #6 on: February 13, 2018, 03:23:13 AM »
Jason bought the bike from me 17 years ago?
He used it for racing and went Expert on it.
But time went on and it became a back up bike...
Then it became a bike for friends to ride.
Then it sat for the last 5 years or so buried deep in the stack of bikes Jason owns.
The amazing thing is that it started up after the second kick...
Jason does own another 98 KX250 that is pristine but that is not what this build is about.
For me, it will be a bit of exploration...
For Jason, he will have a nice engine when it's done  :-D
And some of us will learn new things  8-)
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline Heniz

  • Full Member
  • ***
  • Posts: 68
Re: Project Clapped out 1998 KX250... what works?
« Reply #7 on: February 13, 2018, 03:40:30 AM »
any chance you want to part ways with the rear shock ? I got a spare I could trade + cash your way. if there is anything you want to know about this bike I pretty much know everything I have built 2 1997 / 1998 now within the last year.

such as the LHS sub exhaust valve that is now obsolete..... wears out on the alloy teeth but if it has the 1998 cylinder you can use the 1999 power valve with a slightly different part number that is still available and all measurements are exactly the same. I have the part numbers stashed away on my phone somewhere so let me know if you need them.

also I have a complete bike broken down for parts if you get stuck for anything at all.

 :mrgreen:
Moto is life

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Re: Project Clapped out 1998 KX250... what works?
« Reply #8 on: February 13, 2018, 08:24:44 AM »
any chance you want to part ways with the rear shock ? I got a spare I could trade + cash your way.

This bike belongs to Jason Tanner from JT Engine Works and I can assure you that there is no way he will part with anything from this bike except maybe the seat  :-D

if there is anything you want to know about this bike I pretty much know everything I have built 2 1997 / 1998 now within the last year.

Sweet. If you see anything that you would like to contribute, please feel free to post away.
I'm always interested in other helpful opinions.

such as the LHS sub exhaust valve that is now obsolete..... wears out on the alloy teeth but if it has the 1998 cylinder you can use the 1999 power valve with a slightly different part number that is still available and all measurements are exactly the same. I have the part numbers stashed away on my phone somewhere so let me know if you need them.

I appreciate your willingness to get the numbers but I have all the parts numbers stashed away here:
http://oem-cycle.com/KAWASAKIKX250BIKEID.shtml

also I have a complete bike broken down for parts if you get stuck for anything at all.

I'm pretty flush on parts for the project but if something comes up I will hit you up.
Thanks again for your willingness to chip in.
That's what makes these forums work  8-)

The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Re: Project Clapped out 1998 KX250... what works?
« Reply #9 on: February 13, 2018, 10:12:29 AM »
The bike started on the second kick..
Amazing that it sat for 5 years in such rough condition and started right up..

After the clean up and start up, Jason decided that he wanted to use a different wheel and tire for the build...
I guess he was concerned about the extra weight..
After installing the tire he discovered that the bearings were junk.
I just happened to have some new mid 90's Yamaha YZ bearings which fit perfectly..
But, he will have to re-use his seals because the YZ seals are a larger diameter then the Kawi seals..
Just for grins I looked up the Rear Wheel HP for the 2018 KTM 250 SX and thought it was a blistering 37.8 hp.
BUt then I saw that it was for the 4T...  :-(


« Last Edit: February 13, 2018, 01:09:24 PM by sandblaster »
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Re: Project Clapped out 1998 KX250... what works?
« Reply #10 on: February 13, 2018, 01:13:31 PM »
Ok... The tire is on and we are ready for our first dyno run...



The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline Heniz

  • Full Member
  • ***
  • Posts: 68
Re: Project Clapped out 1998 KX250... what works?
« Reply #11 on: February 13, 2018, 05:16:29 PM »
Ok... The tire is on and we are ready for our first dyno run...





There is not enough silicone on that motorcycle  :roll: lol.

Yeah I love my 97 kx250 its more of a backup bike for my race bike a 2016 yz250 but I still get around the practice track pretty quick on it.

Mods include.
Applied engineering triple clamps, (unsure of offset)
Race Tech springs front and rear,
Pirelli mid soft 32 tyres,
KHI works cylinder head,
cleaned up 1998 cylinder with fresh Nikasil,
engine cases matched for flow,
Wossner piston,
Hardened Anodised clutch basket,
Jd jetting kit,
Vforce Reed block
Dep sport Factory finish pipe
Pro Circuit shorty tail pipe


and heres how she started out


« Last Edit: February 13, 2018, 05:21:06 PM by Heniz »
Moto is life

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Re: Project Clapped out 1998 KX250... what works?
« Reply #12 on: February 14, 2018, 03:23:16 AM »
Lol... Who doesn't love a bottle of tire shine dumped onto scabby old plastics...
Yes, old iron if set up correctly, and you know how to ride it, can be very competitive especially on the local tracks.
I love seeing the looks of these guys faces that have 12-15k + invested into their new tech and get blown into the weeds by a 20 year old 2T...  8-)

You did a nice restore..  :-o
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Re: Project Clapped out 1998 KX250... what works?
« Reply #13 on: February 14, 2018, 01:49:26 PM »
What I haven't shown is all the bottom end bearings, seals, gaskets, ect that I ordered for this project.
Today I received the last piece..
Gotta love those Wossner products  8-)
So now.. the balls in Jason's court to get get this thing dyno'd and start the tear down..



The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline umberto

  • Administrator
  • Hero Member
  • *****
  • Posts: 2,488
  • First Ride 02-02-19
Re: Project Clapped out 1998 KX250... what works?
« Reply #14 on: February 14, 2018, 02:35:51 PM »
Lol... Who doesn't love a bottle of tire shine dumped onto scabby old plastics...
That plastic renew stuff does really well on black. I did the fender and side panels on that 2003 250 I flipped last year. It’s easy to use, and it doesn’t wash off.
Perhaps I have a dirt bike addiction?

03 KX 250/88 KX 525/2017 KX250F - Goliath
17 KX250F/04 KX250
04 KX 250 - Lunchbox's Bike
05 KX 125/144