125 2001 YZ125

Trfsrfr

Trfsrfr

Fixing the kids 125 today after taking it to the track (I rode it, he wasn't there) and got the new throttle cable working properly, but it's hot AF here right now (85-105) and she's sluggish down low.
Cleaning the carb right now and was wondering, should I jet down, or just drop the needle 1 position?
 
Mihylo33

Mihylo33

Trfsrfr:
Fixing the kids 125 today after taking it to the track (I rode it, he wasn't there) and got the new throttle cable working properly, but it's hot AF here right now (85-105) and she's sluggish down low.
Cleaning the carb right now and was wondering, should I jet down, or just drop the needle 1 position?
Click to expand...

Lean it out.
 
Trfsrfr

Trfsrfr

I'm in love with this bike now.
Almost 20 years old, but damn its fun! Easier to put the power to the ground than my 250, and I sent it way farther all weekend.
And my buddy with the same year KTM125 says its faster.
Definitely keeping it.
 
PALMER84ONE

PALMER84ONE

Trfsrfr:
I'm in love with this bike now.
Almost 20 years old, but damn its fun! Easier to put the power to the ground than my 250, and I sent it way farther all weekend.
And my buddy with the same year KTM125 says its faster.
Definitely keeping it.
Click to expand...
Put the 2002 spring on the governor. You'll love it even more.
 
Trfsrfr

Trfsrfr

I got a cart going at RMATV, and I checked the governor spring numbers.
For the 01-03 its a
90501-26001-00 SPRING, COMPRESSION | (5MV1)
For the 04 its a
90501-30001-00 SPRING, COMPRESSION

Does this ring a bell?

And what is the difference and what does it do?
 
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PALMER84ONE

PALMER84ONE

Still looking in my notes: I believe it is a softer spring so the power in more linear.

It was this one as they used it in up to 2000, then again in 2004 on.

90501-30001-00
 
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