Piston pin pitting *picture


25 replies to this topic
  • Pozi

Posted October 15, 2004 - 11:18 AM

#1

Is this bad? It is on my connecting rod too but not as bad. Should the rod be replaced too?

Inserted picture from better photohosting site!

Posted Image

  • mxcowboy

Posted October 15, 2004 - 01:47 PM

#2

That's not bad, I see a lot of post on here with a RED "X".
I've had a few before until I got away from Imagestation, Now it's all good.
Try another photo hosting web site.

  • YZ250F_Rider

Posted October 15, 2004 - 01:52 PM

#3

Boy I dont know. If mine had a red X pit on it I would be trashing the whole engine.

  • cowboyona426

Posted October 15, 2004 - 04:19 PM

#4

It's kind of hard to tell, but they don't look too deep. I wouldn't sweat it myself, the rod should be just fine. Just put some motor oil in the new pin and watch your oil close after you finish your rebuild for other-than-normal metal shavings in the filter.

  • Pozi

Posted October 18, 2004 - 05:53 AM

#5

Could you view the picture cowboyona426? Most people could not see the picture. I need a GOOD photo hosting site!

Thanks for the response anyway. :cry:

  • cowboyona426

Posted October 18, 2004 - 08:25 PM

#6

I had to copy the URL from the pic and paste it into a new browser. I recently switched to Ofoto, and it seems to work most of the time. I wish I could find a good hosting site too :cry:

OT- where in WA is Poulsbo?

  • sirthumpalot

Posted October 19, 2004 - 02:19 AM

#7

Check your rod to see if it is also pitted. Differently replace the wrist pin and bearings when you replace the piston, if the rod is pitted like that then you will need a new rod too.

  • YZ250F_Rider

Posted October 19, 2004 - 02:34 AM

#8

well now that I have seen the pic. Thats bad man. That pitting looks as though it was caused from gouging it out. Possibly you either got a chunk of gear metal in there or it ran without oil.

I would be surprised to find the rod end didnt have metal missing too.

  • YAMAKAZE

Posted October 19, 2004 - 06:14 AM

#9

I concure, Replace it. The wrist pin and Rod (if Required) are not expensive. You are asking for a seizure on down the road if you don't. I agree it looks like a very small piece of the bearing race may have come off at sometime and caused the scoring. It only takes seconds to to damage like this, and may not have serious consequences for some time, But being out of spec can cause vibrations that over time could very well cause a piston to let go creating a major overhaul or engine replacement situation.

Bonzai :cry:

  • Pozi

Posted October 19, 2004 - 09:20 AM

#10

I concure, Replace it. The wrist pin and Rod (if Required) are not expensive.


I have not pulled the crank yet... What is going to be involved with separating the crank to replace the connecting rod? I thought maybe the whole crank was a one piece sell. First off I do not have a crank puller or installation tool. Can this be done w/o these tools?

I have been also considering a big bore kit. Is a con rod included in this kit?

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Pozi

Posted October 19, 2004 - 10:00 AM

#11

OT- where in WA is Poulsbo?


:cry: Poulsbo is located on the Kitsap peninsula just north of Bremerton. Like the MxPx song "Move to Bremerton" or place of residence for Sir Mix-a-lot.

  • cowboyona426

Posted October 19, 2004 - 06:40 PM

#12

Ohhh, its on "that" side of the state :cry: My wife has family in and around the Seattle area. I've spent a lot of time in the Methow Valley (wifey's home town) :cry:

  • YZ250F_Rider

Posted October 20, 2004 - 02:50 AM

#13

Do a search on the online microfiche sites. I just came across the crank/rod assembly for less than $150. Thats really cheap considering what it is.

  • Pozi

Posted October 20, 2004 - 05:55 AM

#14

Do a search on the online microfiche sites. I just came across the crank/rod assembly for less than $150. Thats really cheap considering what it is.


Please share where you found this online.

  • Pozi

Posted October 20, 2004 - 06:04 AM

#15

Ok. Got some more pictures to share. As you can see below is a picture of the connecting rod....Is it toast???

Also is a picture of the cylinder wall. There are no skratches. Should I have the small cross hatching done again before installing new piston?

Posted Image

Posted Image

  • YZ250F_Rider

Posted October 20, 2004 - 06:15 AM

#16

I can get the link to the fiche this evening for you.

I would call the rod toast, myself.

See the shiny rings at the top of the cylinder. Those are wear spots where the piston rings have worn the cylinder down more than the rest of the bore. It's worn the most right were you need it intact the most. I would just get it re-plated. Although it may be cheaper to just buy a new cylinder though. The same fiche will show that too.

  • Pozi

Posted October 20, 2004 - 09:38 AM

#17

Would a big bore kit eliminate the need to have the cylinder re-plated? After all the $ that is going to go into repairing everything it seems as though it equals the amount of a big bore kit.

  • cowboyona426

Posted October 20, 2004 - 02:02 PM

#18

Yuk, that rod looks bad. I would definitely replace it. As for the cylinder, I'm no expert so I won't open my mouth :cry:

  • YZ250F_Rider

Posted October 20, 2004 - 02:52 PM

#19

well they have raised the "list" prices for the assembly. You'll have to do some leg work calling around to get a low price but you should be able to definitely get below the listed price.

just look your bike up and it will show the list price for everyting on it.

http://www.yamahaaccy.com/parts.aspx

  • Pozi

Posted October 25, 2004 - 06:01 AM

#20

well they have raised the "list" prices for the assembly. You'll have to do some leg work calling around to get a low price but you should be able to definitely get below the listed price.

just look your bike up and it will show the list price for everyting on it.

http://www.yamahaaccy.com/parts.aspx



Thanks for the link. That is a very useful web-site for parts. Everyone should put this in their favorites folders.





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