knocking after new top end

C

cr250dave

Member

Jun 25, 2005

13

0

• Jul 22, 2005

• #1

I have an 03 cr250 that I just put a wiseco piston in. It starts fine and idles good but when going to start breaking it in I noticed that there is a knocking noise after I roll off the throttle. It only does it when the rpms start coming back down and it is not consistant. I will knock a couple times and then stop. I was real careful during the install and did it all by the book. Any advice would be great.

Thanks,
Dave

 

ellandoh

dismount art student

~SPONSOR~

Mi. Trail Riders

Aug 29, 2004

2,958

0

• Jul 23, 2005

• #2

possible lean condition????

 

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cr250dave

Member

Jun 25, 2005

13

0

• Jul 23, 2005

• Thread starter
• #3

You might be right I will check that out. Any other ideas??

 

bclapham

LIFETIME SPONSOR

Nov 5, 2001

4,340

0

• Jul 23, 2005

• #4

sounds like an air leak- maybe buy another base gasket and double check the sealing surfaces.

check the manifold and carb is bolteted up OK also.

 

S

Sandy Whoops

Member

Oct 11, 2003

74

0

• Jul 23, 2005

• #5

Did you happen to change your premix ratio for the break-in? And is your gas fresh?

 

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cr250dave

Member

Jun 25, 2005

13

0

• Jul 23, 2005

• Thread starter
• #6

Pre mix was the same and new gas. I richened up the needle and the main jet and took it out today. It sounded great I thought I had it rich enough before but I guess not. Anyway thanks for the help guys its all broken in now.

 

Pete Payne

MX-Tech Suspension Agent

Nov 3, 2000

933

38

• Jul 23, 2005

• #7

sounds like it could be a lose heas stay or motormount . They tend to onlyvibrate on the decel when loose .