piston diagnostic pictures: 2000 KX65

M

MXTex

~SPONSOR~

Feb 29, 2000

417

0

• Dec 11, 2002

• #1

Included herein is a picture of the piston out of my son's 2000 KX65. I just bought this bike used and pulled the top end for a maintenance check. Needless to say, I'm going to be installing a new piston kit. I'd appreciate any feedback on these exhaust port side scuff marks on the piston. The cylinder looks fine. Could this be indicative of another problem or is this normal wear? I believe this is the original piston and the bike seemed to run fine; although we're coming off an XR50. Thanks in advance.

 

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M

Matt_H

Member

Sep 13, 2001

365

0

• Dec 11, 2002

• #2

That is alot od blow by on that piston it should have been replaced awhile ago.

 

1

125 rider

Sponsoring Member

Oct 1, 2000

408

1

• Dec 12, 2002

• #3

That looks like some heavy exhaust side scuffing.

 

M

MikeyG

Mod Ban

Nov 28, 2002

100

0

• Dec 13, 2002

• #4

Does this bike have a Powervalve?

 

M

MXTex

~SPONSOR~

Feb 29, 2000

417

0

• Dec 13, 2002

• Thread starter
• #5

no powervalve

 

Jaybird

Apprentice Goon

LIFETIME SPONSOR

Mar 16, 2001

6,449

0

Charlestown, IN

• Dec 13, 2002

• #6

How does the jug look in the area where the blow-by is?

 

MikeT

~SPONSOR~

Jan 17, 2001

4,095

11

• Dec 13, 2002

• #7

I was going to say that you need to drill those holes in the piston behind the exhaust port bridge, but it looks like you did. It might be a sign of a cold seizure early on in the pistons life and it just broke free.

 

KenR

Member

Feb 20, 2002

193

0

• Dec 13, 2002

• #8

Looks like a cold seize to me. Make sure junior warms that bike up real well before putting a bunch of load on the engine. We used to replace the ring on our 65SX after every few races. You'll get a lot more life out of the piston by frequent ring changes.