Help 06 Yz450F Fork Seals Blown 3x in one month

11 replies to this topic
  • 757holeshot

Posted March 23, 2006 - 12:48 AM


as mentioned above my seals have blown 3 times in three weeks why? acording to yamaha (whom have replaced the seals twice already and now a 3rd time )have said they had to replace the whole inner fork assy to fix the problem on a 06 250 2 stroke but it looked fine no "bowing" on the legs everything within spec................ANy way ive only had it 3 months(bike rocks) and all of a sudden this starts happinin i wana know if any1 has heard of any faults with the forks??? and maybe shed sum light on it for me


  • Ga426owner

Posted March 23, 2006 - 06:01 AM


This can be attributed to several things.
Do you ride in wet muddy conditions? All it take is one spec of dirt to get up into the seals to cause leaking - clean the seals better after riding/washing with a credit card or similar
Did you forks get hammered by roost and rocks? A small ding on the fork leg will cause this to happen

  • Nalgene

Posted March 23, 2006 - 06:08 AM


Hey bro I have an 05 450 *bought brand new* my right front fork seal has gone out twice. The warnty only picked up the tab for one of the blow outs. The other blow out happened after the 30 day warnty.. :thumbsup: They have found no reason why my seals went out.. I ride mostly sandy desert stuff.. and I make sure to wash the bike after every ride, but dont use the pressure washer any where NEAR the front seals.

  • Matt96xr6

Posted March 23, 2006 - 08:19 AM


inspect the inner fork leg.

Also replace the fork bushings and the DUST WIPER when you install seals again.

If you still have problems, you either have a bent fork leg or gross installer error. First time TC installers can have problems with seal installs. IF you let the inner legs go to full travel when the IC is out, the diameter on the inner fork leg is thinner. If you try to just shove it back in, good chance of folding or pinching or tearing a seal. Again, installer error.

  • Blue Rider 236

Posted March 23, 2006 - 12:51 PM


Try this:

Maybe the shop is damaging the seals durring install. They could be using cheap after market seals. Yamaha seals are the best but after markets are cheaper.

  • jeffboyd47m

Posted March 23, 2006 - 04:07 PM


I have stopped leaky seals many times by simply popping off the dust seal, squirting the seals out with contact cleaner and then working a piece of tear off in and out of the oil seal completely around it. It just takes one grain of sand or dirt to make your seal leak. Try it! It will make a believer out of you.

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  • 757holeshot

Posted March 23, 2006 - 04:16 PM


wont it just push all the contaminates into my forks


Posted March 23, 2006 - 04:17 PM


to clean, insert film negative strip along fork tube and seal......... then pack with small amount of grease............

  • 757holeshot

Posted March 23, 2006 - 04:25 PM


ok then ill give it a go if it happins again

thanks all

  • Matt96xr6

Posted March 23, 2006 - 06:28 PM


Yamaha seals are the best but after markets are cheaper.

You know, you say this thinking you are saying something smart here. But in reality it just shows what you dont know.

NOK is the brand of seals that is most common in the automotive and motorcycle industry. NOK is the brand that Yamaha uses from the factory most all the time.

Now aftermarket seals also use the SAME NOK brand seal. Even the "cheap" bikemaster brand, ProX and many others.

So is the smarter person -- buying the Yamaha NOK seal for more than the Bikemaster NOK seal???? You are buying the same seal, why not get the best price????

The only different seals I have seen out on the market are the new MSR units with a triple lip design. Factory connection uses a bit thicker seal but then has to use a thinner washer so it all fits under the bell clip.

  • jeffboyd47m

Posted March 23, 2006 - 09:13 PM


wont it just push all the contaminates into my forks

No because you clean any dirt that is outside of the seal off with the contact cleaner. Once you push up through the seal the tear off bottoms out against the fork bushing. All you are trying to do is dislodge anything that does not belong there.

  • Blue Rider 236

Posted March 24, 2006 - 09:40 AM


I am saying this with experience. I have used both types of seals. I have had very bad luck with pro x seals= AFTERMARKET! They don't fit like the YAMAHA seals do. What makes you an expert on what company the factory and aftermarkets use to make there seals. Show me some proof then I will believe you and your comment about me not being that smart will be justified.

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