how longs, to long for a piston

[motox crf250r]

my brothers 2005 yz450 has got the same piston in it for 4 years now. it has been ridden alot but he does not race but it gets riden pretty hard. Should he stick with it like the saying says, if its not broken dont fix it? or be safe and change it? just like to hear your opinions.thanks

[Lota Fun R]

I have an 01 426 that I'm sure has the stock piston in it and it runs pretty good.

Only if you want peak performance would this matter.

Unless I've over looked something.

Having said that I'm contemplating refreshing the top end......thanks....

[yamiguy51]

i got 140hours on my 07 450 still runs great and starts fine. dont know when to change the thing

[BC3]

My 03 450 still has the stock piston in it and it has good compression and doesn't rattle, but to be safe I think if you ride a lot and hard I would freshen it up with a new piston and rings. Check the taper before buying anything it may need a bore also.....

[Smokeslider]

have it leak tested and you'll know how things are doing.

[Yamiryder]

replace the piston. you'll wish you did when it blows up and you have to buy whole new engine.

[i_wheelie_longer]

Alot of people seem to overlook the wear/stress on the wristpin. It only makes sense to spend about $200 for a new piston, rings, wristpin, and gaskets rather than wait for something to break and destroy your valves and head.

[642MX]

Some of you guys are killing me...

Rings - every year (or 100 hrs)

Timing chain - every year (or 100 hrs)

Piston - every other year

Valve Springs & seals - every other year

Mains & big end bearing - 600 hrs or so

I may do too much maintenance, but when I want to ride, I want to ride... not sit at home cause my bikes broke.

[Brawg]

Dido!

[Brawg]

replace the piston. you'll wish you did when it blows up and you have to buy whole new engine.

DidO!!!!!!!!!!!!

[rufusz]

dido? what does dido mean?

[grayracer513]

"Dido" is a girl's given name, a diminutive of "Diane". What he meant was "ditto", meaning he agrees with the previous poster.

[Brawg]

"Dido" is a girl's given name, a diminutive of "Diane". What he meant was "ditto", meaning he agrees with the previous poster.

Diddo!

[Brawg]

Sorry, Ditto!