Compression?

C

chronicjohn

Member

Oct 27, 2003

2

0

• Oct 27, 2003

• #1

Ive just rebuilt my top and bottom end of my first dirt bike-a 1985 yz125. What is the specified compression for this bike? Im getting about 120 psi but I think this is low.

 

marcusgunby

LIFETIME SPONSOR

Jan 9, 2000

6,450

2

• Oct 27, 2003

• #2

You want at least 150psi.

 

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Studboy

Thinks he can ride

Dec 2, 2001

1,818

0

• Oct 28, 2003

• #3

Did you check the ring end gap? Are you testing with the throttle full open?

 

C

chronicjohn

Member

Oct 27, 2003

2

0

• Oct 31, 2003

• Thread starter
• #4

Whats the ring end gap? And no, im not testing with the throttle open. Should I? And also Im testing at cold conditions not operating conditions.

 

J

jboomer

~SPONSOR~

Jan 5, 2002

1,420

1

• Oct 31, 2003

• #5

Sounds like you're doing it ALL wrong. You should be testing it on a warm engine, with the throttle wideopen, and keep kicking until the gauge quits rising (5 or 10 kicks).