Why would one replace spark-plug, gaskets, pistons, orings, exhaust on a 03' 400ex??

[BT77]

I bought an 03' 400ex sight unseen and will pick it up on Tuesday. Owner said that spark-plug, gaskets, pistons, orings, & exhaust were recently replaced and the bike is "almost like new". I owned a 00' 400ex but sold it after a few months to get into street bikes so I'm pretty familiar with the machine.... I'm scrathing my head why a bike would need all of the above parts if it is only a year old. Any input or suggestions are welcome.
Thanks,
BT

[Bill Fuller]

Well replacing the plug is normal,at least once a year I do the same.As far as the other stuff,is it the same bore?If not than you replace the rings when boreing and replacing the piston.Same goes for the gaskets.I don't know what is meant by orings,maybe exhaust gasket when peplacing the pipe.I hope everything works out for you I wouldn't be worried about the described upgrades,I would however be concerned about buying anything sight unseen.:eek2:

[smith_400ex_213]

how old was the owner

[440ex kid]

I replace the gaskets and ring almost twice a year just to keep it running strong. Maybe he just rebuilt the motor so it ran good so he could sell it. Seems logical to me.

[daimon1054]

The 400ex will suck water pretty easily so if he did that he would have needed a top end job. As long as it was done right, no problems.

I used to rubuild a top end every 3rd race or so but that is really overkill.