KX and cracked piston skirts

B

bent31

Member

Oct 16, 2003

1

0

• Jan 13, 2004

• #1

My son had 2 KX-85's and now we have a 2003 KX-125 3 months old. Both his 80's and this 125 , now, the front of the Piston Skirt cracks. Are kawasaki's known for this? He does race and really stays in each gear too long, is that what is causing the cracks? Just wanting some thoughts.

Thanks

 

R

RM Dan

Member

Mar 28, 2000

5

0

• Jan 13, 2004

• #2

Are you talking about the front part closest to the exaust ports? If so, might be running to lean. Have you recently changed the pipe or anything? Needle or any carb parts? Also if you could post a pic might be able to help more.

 

S

Studboy

Thinks he can ride

Dec 2, 2001

1,818

0

• Jan 13, 2004

• #3

How long have you been running the bike in between piston and ring changes? Airfilter maintenance?

A hard rider on a 125 can wear out pistons quickly.

 

M

mdmader

Member

Oct 9, 2001

31

0

• Jan 17, 2004

• #4

According to Eric Gorr's web site, the crack are due to the clearance between the piston and skirt are too great.

http://ericgorr.com/twostktech/pistondiaguide_2t.html

Looks like you caught it in time. Any longer and the skirt would have exploded causing serious damage.

I had this happen to my 01 YZ250 late last year. Put a nice gash in the cylinder and bent the rod. Sent it Eric Gorr and his shop did a nice job of putting back into shape.

That's my .02 worth.

-M

 

rickyd

Hot Sauce

Oct 28, 2001

3,447

0

• Jan 18, 2004

• #5

I would see if the cylinder is out of bore, if it is, the skirts hang up on the exhaust port, causing them too break.. Had this happen on a 89' yz250..
Rick