How long should you "take it easy" on a new top end?

Y

yamikawi21

Member

Oct 21, 2008

19

0

• Dec 6, 2008

• #1

I have a 97 YZ125. Brand new piston, ring, rod, needle bearing, cylinder honed, gaskets, spark plug...new top end.

How long should I ride slow and under lower RPMs before I can open it up again?

 

C

crkid33

Member

Jun 20, 2007

83

0

• Dec 6, 2008

• #2

i rode mine around for 10 mins taking it easy. then let it cool all the way down. Then i just ride it like normal

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Dec 7, 2008

• #3

Idle till it warms up, cool down. Repeat. Then take a ride till it warms up, and no full throttle. Then a 15 minute ride no full throttle. Then it should be good.

 

MikeT

~SPONSOR~

Jan 17, 2001

4,095

11

• Dec 7, 2008

• #4

Let it warm up then rip. Really there is no big break in with a 2-stroke in my book. The rings are so small that they are good to go as soon as everything warms up.

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Dec 7, 2008

• #5

Mike, that sounds like a spark plug break in? Its a fresh bore and top end.

 

J

_JOE_

~SPONSOR~

May 10, 2007

4,697

3

• Dec 7, 2008

• #6

Bearings need to run in for a little while before really running it hard. I do a couple easy runs with a cool down between then call it good. A plated cylinder and modern rings generally don't need to be babied after a rebuild.

 

Z

zrxrider

Member

Nov 24, 2008

55

0

• Dec 9, 2008

• #7

yamikawi21, what kit do you use? I'm thinking of ordering the Wiseco kit.......

I would take it easy(no full throttle) for the 1st 1/2 hr then let her rip!

 

J

JD-250

Member

Sep 6, 2003

47

0

• Dec 13, 2008

• #8

You will probably get about 20 different opionions on the subject and then be even more confused then before. Find the owners manual and follow what the factory recommends for break-in.

 

Y

yamikawi21

Member

Oct 21, 2008

19

0

• Dec 22, 2008

• Thread starter
• #9

Good idea JD - too bad i just read your advice :P
I let it run (around idle) for 20 minutes two seperate times. Then a couple easy rides up and down the road. Then took her out and had a blast. Faster then my bike has ever been!

zrx - I ordered the "top end kit" with Wiseco piston kit and Cometic gaskets from Motosport magazine. Its the cheapest price I could find. and so far Im very happy with the products. Good luck