CR125 Cylinder Help

bonseff
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bonseff

Can anyone help identify what year cylinder this CR125 cylinder came off of? I attached photos with the only discernible markingsIMG 3770 0IMG 3771IMG 3772IMG 3773.jpg?VersionId=WDgFIMG 3774IMG 3775.jpg?VersionId=.a3sEx6n.iJphJ

 

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Last2Stroke 12/8/2025 4:55pm
12/8/2025 4:55pm

The photos aren't clear, what is the letter/number on the intake side?

bonseff
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bonseff 12/8/2025 5:44pm
12/8/2025 5:44pm

oY / 6

is the best i can make out of it

 

bonseff
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bonseff 12/8/2025 5:50pm
12/8/2025 5:50pm

The main reason I am asking is because i have a 96 and found this cylinder on FB marketplace and didnt know if there would be any issues in having this as a backup.

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bonseff
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bonseff 12/8/2025 6:50pm
12/8/2025 6:50pm

Gracias, señor!

SmokinJoe439 12/12/2025 1:48am
12/12/2025 1:48am

It's also been sleeved 

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toomey706
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toomey706 1/17/2026 5:52am
1/17/2026 5:52am

The first five numbers on that cylinder look like a Rat Racing. i've picked up four or five cylinders on bikes here in Texas that were there, primarily in the 90s.  The serial numbers start with RAT and then have two or three numbers after  They were a company in Alvin, Texas, not sure if they're around anymore. 

 Like smokin Joe said, looks like a sleeve in there,  and pretty much worthless at that point.

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bonseff
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bonseff 1/17/2026 7:34am
1/17/2026 7:34am
toomey706 wrote:
The first five numbers on that cylinder look like a Rat Racing. i've picked up four or five cylinders on bikes here in Texas that were...

The first five numbers on that cylinder look like a Rat Racing. i've picked up four or five cylinders on bikes here in Texas that were there, primarily in the 90s.  The serial numbers start with RAT and then have two or three numbers after  They were a company in Alvin, Texas, not sure if they're around anymore. 

 Like smokin Joe said, looks like a sleeve in there,  and pretty much worthless at that point.

Wow - thanks dude! Looks like Rat Racing is still a thing
https://www.facebook.com/mxratracing?mibextid=ZbWKwL

Having a sleeved cylinder is worthless? The one currently on the bike is a sleeved 134, and this one measures the same. 

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