How-To: YZ250F WR250 Top & Bottom End Rebuild

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Josh took me up on my engine rebuilding + video service  for this 2007 YZ250F engine featured in this video. This motor blew the large end connecting rod bearing and sent metal everywhere! Does your YZ250F or WR250 need rebuilding? You can totally fix it yourself instead of paying a shop when you follow along with this step by step video. The video series is actually 3 parts and totals 5 hours in length:

  • Bottom end – 2 hours 30 minutes long, video starts with engine removed from frame.
  • Top end – about 2 hours long, completed while engine is in frame.
  • Valve adjustment – 1 hour long and is a maintenance item that every owner should learn how to do properly.



Year, Make, Model

The following models are covered in this video:

  • YZ250F – 2002 thru 2013 exact, will help on 2014+
  • WR250 – 2001 thru 2007 exact, will help on 2008+


Service Manual

Yamaha YZ250F OEM Service Manual


Below are links to tools used in the video. Some of the link are affiliate links and support me at NO COST to you.

Motion Pro Gear Jammer 08-0427

Motion Pro 08-0026 Flywheel Puller M27X1.0 L.H

Torx bit set

Motion Pro Clutch Holder Tool 08-0008

Vessel Megadora 980 Impacta P2x100 #2 JIS Impact Screwdriver

Milwaukee M18 Fuel ¼” impact

Seal puller

IR thermometer

Tillman welding gloves

Tusk blind bearing puller

Pen magnet

Titan scraper

Super scraper

Exacto knife

Loctite 242

Threebond 1184

Blowtorch kit

Crocus cloth

Deadblow hammer



All OEM parts were used for this rebuild. Make sure to check out if you need to order parts for your project. If you choose to buy from, you are supporting me at NO COST to you.




Has this video helped you out? Please comment below.


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