wrist pin

7 replies to this topic
  • yzf

Posted July 14, 2001 - 08:51 PM


i just istalled a new top end (wiseco)in my yz400. after breaking the bike in i noticed the engine was making a tapping noise. after a few rides the noise got louder so i disided to take her back apart (i let a few people listen to the noise and everybody thought i was crazy to take it apart but i knew the bike did not make this tapping noise befor the top end) guess what i found? if i so much as started the bike one more time i might have been in a lot of trouble, after taking the circlips out of the wiseco piston when i went to take out the wrist pin (pushed it out with my fingers just like i did to put it in) it came out in three pieces

  • yzf

Posted July 14, 2001 - 08:59 PM


I checked every thing inside it all lookes perfect except the wrist pin that came with the wiseco piston (i won't be using wiseco again) so i disided to do the crank so i can change the rod just to be safe even though it looks fine.(three years on bottom end it couldn't hert) has anybody heard of this before? the wrist pin has no discoloring or scoring just cracks and broken into peices i guess it must have been defective??

  • Hick

Posted July 15, 2001 - 04:41 PM


Did your Wiseco come with a wrist pin? I think mine did...

If so, I would be ticked, if not, you should probably replace the wrist pin when you replace the piston.

When you installed it was the fit snug? I wasn't able to push mine in manually.

[This message has been edited by Hick (edited 07-15-2001).]

  • sirthumpalot

Posted July 15, 2001 - 05:21 PM


Just to echo what Hick said, I have never seen a 4-stroke wrist pin that slides in easily.

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  • yzf

Posted July 16, 2001 - 02:18 PM


yes it was a new wrist pin, it came with the wisco piston and it was a tight fit but i did manage to put it in with my bare hands. i talked to wiseco and i mailed the piston back to them today i think as soon as they see the pin they will have no problum waranting the piston they said if the wrist pin is found to be defective they MIGHT pay for a new crank ,the rod has some marks on it i plan to replace the lower end even if they won't pay for it just to be safe.

  • yzf

Posted July 19, 2001 - 08:41 PM


i just talked to wiseco today they found the wrist pin to be diffective .they said that they just increased the wrist pin thickness on the new pistons and i must have got an old one. they will replace the piston free, after an hour of arguing with the manager i finnaly got them to replace the rod but they will not cover labor, gaskets, bearings or seals that are needed to rebuild a crank . so basically i got f@$&$!

  • yzf

Posted July 19, 2001 - 08:49 PM


I am a plumber by trade and i asked the manager if i put a new toilet in his house and it leaked and did $10,000 in water damage to his house when he was not home what would he think if i told him i will replace the toilet and leaky pipe but nothing else because his house is not brand new.

  • MotoStyle

Posted July 19, 2001 - 08:56 PM



Here's some food for thought. For about 30.00 you can file a claim in small claims court in your county. Weisco reps will be obligated to show up at your courthouse and will need to argue their point of why they think they shouldn't pay for a new rod replacement. I'd say for 30.00, once they receive the court doc's, you'd have a new rod, bearings, seals, and a letter of apology. That just isn't right. They openly admitted to you that they gave you the wrong wrist pin, but they say that they will only cover certain parts? I'd say, "How about we see what Judge Wapner has to say?"

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