Author Topic: How a Piston and Cylinder shouldn't look  (Read 2440 times)

0 Members and 1 Guest are viewing this topic.

Offline vaaprider

  • Full Member
  • ***
  • Posts: 68
  • He's Ready
How a Piston and Cylinder shouldn't look
« on: June 19, 2009, 03:23:06 PM »
The piston looks bad to me, so does the cylinder.  Look close at what looks like a crack in the cylinder, it does not catch on my finger nail, I hope it is repairable.  The first pics are of the  valve, this is at rest, does this look ok? when I turn it (At the gov. arm) it opens all the way and returns to this position.  Is this a kawasaki piston?, is it what came stock?  Any feedback greatly appreciated.  The crank small end looks to be in spec 24.0 The bottom end feels loose to me, I can rock it, but it measures .018 limit is .020, is the play I feel normal? 

Offline cbxracer30

  • Sr. Member
  • ****
  • Posts: 304
Re: How a Piston and Cylinder shouldn't look
« Reply #1 on: June 19, 2009, 03:54:02 PM »
If the piston has ART cast into the underside it is factory. Clean up the top a wiseco will have numbers on the top. The crack on the bridge is one of those things every K5 will eventually develope sometimes on both sides usually when they repair them they weld up both sides just to be safe. US Chrome and Powerseal I have used to make the repair and replate. You need to hone the cylinder though ,you really arent getting a true look at it until you clean it with a hone then you will see real cylinder.CBX
Yep, you can ride it - if YOU can start it !!

Offline vaaprider

  • Full Member
  • ***
  • Posts: 68
  • He's Ready
Re: How a Piston and Cylinder shouldn't look
« Reply #2 on: June 19, 2009, 04:11:00 PM »
Thanks. Does the valve look ok in the first pics?

Offline martinfan30

  • Sr. Member
  • ****
  • Posts: 456
  • 2000 KX500
Re: How a Piston and Cylinder shouldn't look
« Reply #3 on: June 20, 2009, 03:31:53 AM »
Thanks. Does the valve look ok in the first pics?

Looks OK, just needs to be removed and cleaned well. I had to replace one of the bushings on the bottom of one valve on mine.
2000 KX500
2005 XR650L

Neither are stock, and both are great desert bikes.

Offline hughes

  • Hero Member
  • *****
  • Posts: 1,923
    • Dirt Hammers
Re: How a Piston and Cylinder shouldn't look
« Reply #4 on: June 22, 2009, 04:46:57 AM »
That piston/ring set is just slap worn out. Tons of blow by on the piston.
Open Class 2-Stroke Kawasaki KX500
Yamaha 2005 YZ250
Richard Hughes
Dirt Hammers - Online Off-Road Journal
hughes@dirthammers.com
http://www.dirthammers.com

Offline medicman

  • Jr. Member
  • **
  • Posts: 34
Re: How a Piston and Cylinder shouldn't look
« Reply #5 on: June 24, 2009, 04:15:33 PM »
does that piston wash cause a loss in power? how is that corrected? I just did a top end in my 500 and my piston looked a little worse than that one