I need some help with top end rebuild

MarcPhotoMan

New Member
OK I ordered my parts and I am going to change the piston head and install new rings,
I checked norms 'Bicycle engine total tear down' post I removed the wrist pin but after that I do not know how to remove the piston head from the crank arm.

I am noob to this particular repair, but ready to take it on.

zpt
 

Attachments

  • DSC02020.JPG
    DSC02020.JPG
    195.5 KB · Views: 296
Last edited:
Did you remove the wrist pin keepers? You did remove the wrist pin too didn't you? You remove usually one keeper the little clip thing, and then you can push the wrist pin out on the side that you removed the keeper from if the wrist pin is hard to remove use a wooded dowel to help you push it out and you can warm up the piston by wrapping it with a rag soaked in hot water. Let the rag sit warped around the piston for a bit a couple of minutes should do it then try to push out the wrist pin you might need to remove both wrist pin clips if its hard to remove. Do not beat on it or scratch the pistons wrist pin holes.
Is your wrist pin bushed or is a needle bearing? Either way if the wrist pin is out the piston should come off.
Norman
 
Last edited:
The wooden dowel worked like a charm thanks, I plan to update this post as I move along through my repair. This might eventually help another noob to the top end rebuild!

Pic 1: Here is a pic my bike looking very sad
Pic 2: how a dowel fits into the piston
Pic 3: I believe that is the Tit
 

Attachments

  • sad.jpg
    sad.jpg
    273.1 KB · Views: 240
  • dowel.jpg
    dowel.jpg
    165.9 KB · Views: 278
  • tit.jpg
    tit.jpg
    77.2 KB · Views: 334
Last edited:
Pic 4: Roller bearing
Pic 5: Crank arm
Pic 6: Bottom tit
Pic 7: Crank case before cleaning
 

Attachments

  • roller.jpg
    roller.jpg
    54.3 KB · Views: 231
  • crank.jpg
    crank.jpg
    109.1 KB · Views: 237
  • tit2.jpg
    tit2.jpg
    80.5 KB · Views: 376
  • crank case.jpg
    crank case.jpg
    206.7 KB · Views: 280
I was talking to a coworker about how my repair was going so far.
I told how the pin was hard to take out and that the roller bearing came out easily.

He was saying that when he had repaired his dirt bike that roller bearing was snug in the crank arm, is this the case with these engines?

Do I need an new roller bearing and wrist pin to?
 
Last edited:
The needle bearing and the bushing have the same part number, so my thinking is that They are interchangeable parts
 
Last edited:
Back
Top