Coming Soon
Home > Forum


Author Topic: 2001 KX250 Engine Rebuild  (Read 11065 times)

0 Members and 1 Guest are viewing this topic.

Offline Swimr2DaResQ

  • Expert
  • ****
  • Posts: 137
  • Awww Yeaah!!!
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #15 on: January 16, 2011, 11:22:07 PM »
Thanks for all the great info.
When I pulled the spark plug after it died there was melted aluminum on the plug and it was very hard and sluggish trying to kick it over, so I think it might have broken a ring and also scared up the cylinder wall. I am disassembling the motor this weekend and will know for sure if it will need to be re-plated.
Currently running the V-Force 3 reed valve, with a FMF SST pipe and silencer. I am going to go with the Fatty Pipe and shorty silencer after the rebuild.
I was also looking to get new wheels, and wondering if the 03-07 kx wheels would fit and if the hubs and axles are the same size?
"Technology frightens me to death. It's designed by engineers to impress other engineers, and they always come with instruction booklets that are written by engineers for other engineers - which is why almost no technology ever works."

Offline TotalNZ

  • Expert
  • ****
  • Posts: 247
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #16 on: January 16, 2011, 11:32:20 PM »
hmmm sounds like you should check your jetting and check for airleaks in your manifold, don't wanna melt your new piston too.

Offline Swimr2DaResQ

  • Expert
  • ****
  • Posts: 137
  • Awww Yeaah!!!
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #17 on: January 17, 2011, 12:03:50 PM »
I think that one of my crank seals was leaking, causing it to run very lean. I will be replacing all seals and gaskets and unfortunately I have to split the cases to change the crank seals, but I planned on splitting them any way to check everything out and replace the crank bearings at least. I also just read that Kawasaki say's to change the crank seals every two years or as needed, I'm pretty sure they haven't been changed in a few more years than that!
I have put over 100 hrs on this bike since I bought it in Sep of '08, I don't know how many hours it had on it when I got it, so I guess it was time for a rebuild. I was down in OR at the dunes when it died, we were at sea level to 150',  I had the jetting dialed in for about 1000', not sure if that had a lot to do with it.

"Technology frightens me to death. It's designed by engineers to impress other engineers, and they always come with instruction booklets that are written by engineers for other engineers - which is why almost no technology ever works."

Offline MyckMcClung

  • Professional
  • *****
  • Posts: 812
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #18 on: January 17, 2011, 04:01:10 PM »
the wheels won't fit,
while you have the cases apart go ahead and replace the crank and output shaft bearings/ seals too. definitely replace the waterpump seal,  altitude won't really matter that much under 2000 feet, it was time for your motor to go long before it went.
If a pair of 2" brass balls isn't working, I doubt that the 3" model will make much difference.

Offline Swimr2DaResQ

  • Expert
  • ****
  • Posts: 137
  • Awww Yeaah!!!
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #19 on: January 17, 2011, 04:22:29 PM »
The 2001 KX250 responds very well to porting, cylinder head modification and
a Wiseco super light flat top piston (#704PS).  This piston was developed and
used by Team Kawasaki and allows the bike to rev faster.  The stock ports are
small and the port timing causes the engine to fall flat early.  The head work is
required for the flat top piston.  These mods really wakes up the engine across
the power band.  The bike already has a nice Keihin PWK Air Striker carburetor. 
Bolt on a Rad Valve and Pro Circuit pipe and silencer to complete a very stout
package. 

dogger




Thanks Dogger, I have been looking for the wiseco flat top piston and cannot find it online, do you know where I can order it from and what type of head work or mods need to be done to utilize that type of piston.
I was also wondering if the "Racer's choice" GP style piston is similar?

 
to MyckMcClung,
Thanks on the wheels, my rear hub is cracked and my rims are in pretty bad shape too. I found a nice used set of wheels on ebay, but they were for the 03-07 series.  I guess I'll have to piece together the new wheels.
"Technology frightens me to death. It's designed by engineers to impress other engineers, and they always come with instruction booklets that are written by engineers for other engineers - which is why almost no technology ever works."


Offline Swimr2DaResQ

  • Expert
  • ****
  • Posts: 137
  • Awww Yeaah!!!
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #21 on: February 04, 2011, 07:23:03 PM »
Can anyone recommend a good shop to replate my cylinder? The cylinder wall is pretty scarred up, the dome and the piston had alot of pitting!
Thanks
"Technology frightens me to death. It's designed by engineers to impress other engineers, and they always come with instruction booklets that are written by engineers for other engineers - which is why almost no technology ever works."

Offline MyckMcClung

  • Professional
  • *****
  • Posts: 812
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #22 on: February 05, 2011, 07:31:06 AM »
If a pair of 2" brass balls isn't working, I doubt that the 3" model will make much difference.

Offline MyckMcClung

  • Professional
  • *****
  • Posts: 812
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #23 on: February 05, 2011, 07:35:23 AM »
here's the replating page comes with a piston kit too for the price, comparable to the  cost of just sleeving it.

http://kustom-kraft.com/NEWNIKASIL.html
If a pair of 2" brass balls isn't working, I doubt that the 3" model will make much difference.

Offline Coop

  • Global Moderator
  • Professional
  • *****
  • Posts: 2183
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #24 on: February 05, 2011, 07:36:02 AM »
A lot of people either recommend KK or Millennium for plating.
- Mike - Don't take life so seriously, nobody gets out alive.

Offline SachsGS

  • Professional
  • *****
  • Posts: 1235
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #25 on: February 05, 2011, 09:00:25 AM »
Is the crank o.k. on that KX?When I hear "sluggish to kick over" and "scoring in the cylinder" it almost sounds like your crank has failed. :-X

Offline Swimr2DaResQ

  • Expert
  • ****
  • Posts: 137
  • Awww Yeaah!!!
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #26 on: February 05, 2011, 10:10:41 AM »
The lower end rod bearing failed and sent metal flakes and chunks into the cylinder. The crank will be replaced, probably hot rods or wiseco, stock is quite a bit more expensive! The local dealer uses Millenium Technologies for cylinder replating, I will probably go with millenium, but Kustom Kraft Looks to be a better deal as it comes with a piston!
"Technology frightens me to death. It's designed by engineers to impress other engineers, and they always come with instruction booklets that are written by engineers for other engineers - which is why almost no technology ever works."

Offline factoryX

  • Professional
  • *****
  • Posts: 855
  • Hurry! Follow the other farting sheep!
    • View Profile
Re: 2001 KX250 Engine Rebuild
« Reply #27 on: February 06, 2011, 01:16:22 AM »
on the Hot Rod tip..... I've used them in the last two crank rebuilds i've done, the first was five years ago, over 100 hours, 3rd piston, not even a notion of any wear.
Just installed the second, I'll let you know how that goes.
I've found that most guys that bash aftermarket parts cause it failed on them, usually have a half waffle grip on the left bar, that is an inch from the end and the waffle is in their palm. ;)
LMFAO: "The blue rod of death."


I ride an 03 yz250, wait 04, wait 05, what ever, they're all the same #$@% YOU!