450 top end life?

3 replies to this topic
  • btray

Posted December 25, 2007 - 06:44 AM


How many hours should you put on a top end before piston and ring replacement?

thanks bill

  • grayracer513

Posted December 25, 2007 - 08:39 AM


If you're racing it almost every week, then it's probably a good idea to do it annually. If your use of it is mostly recreational, there's no telling, but they'll go a very long time before they need it. My '03 has never been apart.

The best way to check on how the rings are doing is a leak down test.

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  • btray

Posted December 25, 2007 - 07:20 PM


Thanks Gray...I figured you had probably the best idea since you have my generation yzf...I've had it since May and the guy that had it before me had it maintained at a local race shop and only rode it a couple hours a month for 3 years and he's 45 and weighs in around 250 so my guess is as he chased his son around the track it's still fairly fresh...the leak down check was also recomended by another guy I know...do you know where to find the numbers for this bike...04 450?

Thnaks Bill

  • grayracer513

Posted December 26, 2007 - 12:25 AM


Most leak down tests are done at a base pressure of 100 psi, if for no other reason that it makes the math simple. IMO, a really good, seated fresh engine will leak less than 2%, and an engine that is starting to tire will be around 5%.

Maybe some of the day to day shop wrenches can put their two cents in on that point.

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