If your dirt bike isn't performing as well as it once did or you just have too many hours on it since your last rebuild, its a good idea to service your top end. With a little patience and a few tools, there is no reason why you can't tackle the job yourself. I'll take you through the entire process step-by-step on a 2007 Honda CR125 (including how to rebuild your RC Valves or "Power Valves") so even a beginner can have confidence that they rebuild their top end right.

★SPONSORS and FRIENDS
Special Thanks to: www.TBoltUSA.com

★TIMESTAMPS
0:00 Intro
0:52 Drain Radiator Fluid
1:13 Remove the Seat
1:22 Remove Radiator Shrouds
1:28 Remove Fuel Tank
1:52 Remove Upper Radiator Hoses
2:13 Remove Spark Plug Cap
2:16 Remove Lower Radiator Hoses
2:27 Remove Lower Radiator Mount
2:35 Remove Hanger Plates
2:41 Remove Spark Plug
2:44: Remove Exhaust
3:02 Loosen Cylinder Head Nuts
3:15 Remove Exhaust Flange
3:28 Cycle the Piston to TDC
3:35 Remove Power Port Valve Cover
3:40 Disconnect Power Port Mechanism
3:50 remove RC Valve Cover
3:56 Remove the Cylinder Nuts
4:12 Remove the Cylinder
4:46 Remove RC Valve (Power Valve) Flaps
5:41 Clean Carbon Deposits From Exhaust Port and RC Valves
6:43 Replace Cylinder Studs
8:19 Install RC Valve (Power Valve) Assembly
10:01 Identifying OEM Pistons ("A" or "B")
10:15 Installing A Piston Ring
10:48 Installing Wrist Pin Circlips
11:21 Installing A Piston
12:16 Install A Cylinder On A Two Stroke (Honda CR125)
13:24 Install A Cylinder Head On A Two Stroke (Honda CR125)
14:23 Torque Cylinder Nuts
16:07 Torque Cylinder Head Nuts
16:22 Reconnecting RC Valve (Power Valve) Actuator
16:57 Install RC Valve (Power Valve) Covers

★AFFILIATE LINKS (I MAY MAKE A COMMISSION FROM SALES GENERATED VIA THESE LINKS)
Products Used:
Hemostat Kit (You Will Be So Glad You Bought These!): https://amzn.to/3Z0n2ZT
Oven Cleaner: https://amzn.to/3m47ZzS
Assembly Lube: https://amzn.to/3EzuLGa
Assembly Grease: https://amzn.to/3IlFp4g
LocTite Blue: https://amzn.to/3SH4oUN
Anti Seize: https://amzn.to/3m7dvBB
Permatex RTV: https://amzn.to/3xNMiXc
Torque Wrench (Low Torque): https://amzn.to/38onM2V
Torque Wrench (Best Value): https://amzn.to/3rIVvvD
Disposable Shop Towels: https://amzn.to/3bw3NRS
Hook and Pick Set (Best $10 I Ever Spent): https://amzn.to/3rJ50Lj
Socket Phillip: https://amzn.to/3ceGomV
Mini Flashlight: https://amzn.to/30rwYip

Video Production Tools:
Camera - Canon M50: https://amzn.to/3qupANX
Camera – GoPro Hero 9: https://amzn.to/2O96Lmq
Softbox Light: https://amzn.to/3epcwHk
Neewer LED Lighting: https://amzn.to/3t23Sm3
Microphone: https://amzn.to/3ckzRr3
Sound Recorder: https://amzn.to/3etXFLP
Camera Tripod - Low Height: https://amzn.to/3rA9zqU
Camera AC Power Adapter: https://amzn.to/2PCLEsP

★USEFUL LINKS
VIDEO: Measure Your Top End Right - Watch This!
   • Tips and Tricks For Measuring Your To...  

★MUSIC CREDITS
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Track: Tribute — Ason ID [Audio Library Release]
Music provided by Audio Library Plus
Watch:
Free Download / Stream: https://alplus.io/tribute
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Grut
   • (Grut) | Audio Library: Free Copyrigh...  
Copyright free music for youtube videos
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How About Nah • roljui
How About Nah
℗ YouTube Audio Library
Released on: 2018-02-01
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Dude • Patrick Patrikios
Dude
℗ YouTube Audio Library
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Mellow Out by Ghostrifter Official   / ghostrifter-of.  .
Creative Commons — Attribution-ShareAlike 3.0 Unported — CC BY-SA 3.0
Free Download / Stream: http://bit.ly/l-mellow-out
Music promoted by Audio Library
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Summer Madness by Roa   / roa_music1031  
Creative Commons — Attribution 3.0 Unported — CC BY 3.0
Free Download / Stream: http://bit.ly/l-summer-madness
Music promoted by Audio Library    • Summer Madness – Roa (No Copyright Mu...  
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Good For You by THBD   / thbdsultan  
Creative Commons — Attribution 3.0 Unported— CC BY 3.0
Free Download / Stream: http://bit.ly/2PgU6Mu
Music promoted by Audio Library    • Good For You – THBD (No Copyright Music)  
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Alaska Sky • Patrick Patrikios
Alaska Sky
℗ YouTube Audio Library
Released on: 2019-10-25
   • Alaska Sky