Rebuilding a Yamaha F255TXRC Outboard Part 3: Bottom End Teardown

After stripping the top end from our Yamaha F225 outboard, it's time to strip the bottom end so we can replace any worn parts and start rebuilding it. 

This guide is a companion to our Yamaha F225TXRC Outboard Rebuild Part 3 video, which shows you how to disassemble the bottom end of the motor. The steps covered in this episode include removing the following components and parts:

  • Cooling cover
  • Crankcase cover
  • Pistons
  • Crankcase
  • Crankshaft

We recommend you watch the video above and print the step-by-step guide below to use as a checklist while you work on tearing down the bottom end. Use our Yamaha F225TXRC outboard parts diagrams to see how all the components come apart and fit back together again.

Tools Needed - Yamaha F225 Outboard Bottom End Teardown

  • Ratchet and extensions
  • Socket set
  • Screwdriver
  • Dead-blow hammer
  • Zip-lock bags

Yamaha F225 outboard bottom end teardown

NOTE: Although an impact wrench is fine for disassembling an outboard, it should never be used to reassemble one, as it is too powerful and will easily strip threads or shear bolts. 

Tearing Down a Yamaha F255TXRC Bottom End

PRO TIP: Collect the nuts, bolts, screws, washers, etc. from each component as you remove them, put them in a zip-lock bag and label it. This makes it much easier to find the correct part for the correct component when the time comes to reassemble the motor.

Step 1. Remove the cooling cover, which is numbered to show the tightening sequence for the 13 bolts. To remove the cover, loosen the bolts in the reverse number sequence from 13 to 1. Once the bolts are removed, insert a screwdriver into the pry points at the top of the cover and pry it free from the crankcase, being careful not to damage the mating surfaces of the cover or the crankcase.

Yamaha F225 outboard cooling cover

Watch the clip below to see the cooling cover removal segment of our Yamaha F225TXRC bottom end rebuild video.

Step 2. Remove the oil filter housing complete with oil filter, the oil fill and the linkages.

Yamaha F225 outboard oil filter housing

Watch the clip below to see the oil lines and linkages removal segment of our Yamaha F225TXRC bottom end rebuild video.

Step 3. Remove the crankcase cover, which is numbered to show the tightening sequence for the 17 bolts. To remove the cover, loosen the bolts in the reverse number sequence from 17 to 1. Then, remove the windage tray/baffle plate beneath the crankcase cover.

Yamaha F225 outboard crankcase cover

Watch the clip below to see the crankcase cover removal segment of our Yamaha F225TXRC bottom end rebuild video.

Step 4. Remove the connecting rod end caps. Make sure you remove the end cap bearing along with the cap. Clean and number the end caps so you know which one belongs in which cylinder if you reuse them.

Yamaha F225 outboard connecting rod end caps

Step 5. Remove the pistons by taking a long ratchet extension, reaching it into the crankcase, putting it against the piston base and pressing the piston out of the cylinder block. 

PRO TIP: Be ready to catch the piston as it emerges from the other side of the motor. Clean and number the pistons so you know which one belongs in which cylinder if you reuse them.

Yamaha F225 outboard piston removal

Watch the clip below to see the end cap and cylinder removal segment of our Yamaha F225TXRC bottom end rebuild video.

Step 6. Remove the crankcase from the cylinder block by first taking off the 13 outer crankcase bolts in the sequence shown in the image below.

Yamaha F225 outboard crankcase removal

Step 7. Next, remove the 16 inner crankcase bolts in the sequence shown in the image below.

Yamaha F225 outboard engine bottom end teardown

Watch the clip below to see the crankcase removal segment of our Yamaha F225TXRC bottom end rebuild video.

Step 8. Remove the crankshaft by taking off the oil pump assembly from the lower end of the crankcase and lifting out the crankshaft. 

Yamaha F225 outboard crankshaft removal

Watch the clip below to see the crankshaft removal segment of our Yamaha F225TXRC bottom end rebuild video.

That's the top end of your Yamaha F225 outboard disassembled. Next we will start to rebuild the motor.

Stay tuned for our Yamaha F225TXRC Outboard Rebuild Part 4 video and guide to see how to rebuild the bottom end of your Yamaha outboard.

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