Wtb Yz125 mod cylinder

TheTrackKid
Posts
123
Joined
7/11/2019
Location
Granite Falls, WA US

Wanting to buy 2006-2021 yz125 complete cylinder (with head and power valves) that have had some work done to them. 125cc with port and polish or 134cc with port and polish. No 144cc kits, no Athena kits, reputable engine builders only. 

Thanks!

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TheTrackKid
Posts
123
Joined
7/11/2019
Location
Granite Falls, WA US
2/8/2026 6:11pm

I saw that and I hear good things about them. I was tempted but It’s not the complete kit and I hear a good engine builder can do better with a generic piston, I believe those kits run a special piston, which the seller doesn’t include. 

Carson610
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34
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5/3/2012
Location
Arroyo Grande, CA US
2/8/2026 6:56pm

Why don’t you send your cylinder and head to pro circuit? They are pretty reasonable on their prices. 

TheTrackKid
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123
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7/11/2019
Location
Granite Falls, WA US
2/8/2026 7:16pm
Carson610 wrote:

Why don’t you send your cylinder and head to pro circuit? They are pretty reasonable on their prices. 

I don’t want the down time so if I buy another set up down time doesn’t matter as much, and no down time if it’s already modded. 

1

The Shop

NLMB150
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2/3/2022
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Dying out west, TX US
2/8/2026 8:38pm
johnk408 wrote:
I saw that and I hear good things about them. I was tempted but It’s not the complete kit and I hear a good engine builder...

I saw that and I hear good things about them. I was tempted but It’s not the complete kit and I hear a good engine builder can do better with a generic piston, I believe those kits run a special piston, which the seller doesn’t include. 

You are able to run standard pistons, the gytr ones have a different coating, similar to a vertex or others, and the biggest difference is wrist pin, I don't know what material it is, but its noticeably lighter then stock.  The "High compression" part of the piston is the same as the 22+ pistons being .1mm taller. These kit are similar to the 22+ engines, with the dowel pins in the head, I believe Yamaha used these kits for r&d on the current gen bikes.  Regardless what you do, Its always fun on a yz125.

CrGuy2T
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4503
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3/11/2015
Location
Santa Fe, TX US
2/9/2026 12:21pm

I'm pretty sure Ebr performance in Texas has them on the shelf.. 

2/14/2026 9:12am

How about an RPM 167 stroker motor?

2/23/2026 5:12pm

How about an RPM 167 stroker motor?

You got one for sale?

Yes, a very trick motor complete including pipe & ignition20240815 200807 120240815 20081320240815 200956 1.jpg?VersionId=4g2OAFaChIH.iUgpoRZf7FassIyD20240815 20100520240815 20102020240815 201028.jpg?VersionId=qYt4FOKLmW7Ln43bePApNYI7mzEP20240815 201043IMG 20240815 234644

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johnk408
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1/20/2022
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Ft Mitchell, KY US
2/24/2026 3:20am

That’s a pre aluminum frame motor for sure. Maybe late 90’s?

2/24/2026 9:27pm

I have a cylinder, head and stroker crank that's a 144. Maybe 10 hours total

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