so if I do that and it frees up that means new valves cams and head piston all that

Or some combination there of. Best thing, it means that the bottom end and transmission shaft bearings aren't seized, and that the piston isn't welded to, or turned sideways in the cylinder.

Still no way to tell what is up until you can have a look into it. Buy it on the theory (and $$ offered) that the motor is completely destroyed. Then anything less in the way of damage is a bargain.


The '06-'09 models are dry sump, yes, but the oil is stored in the front section of the crankcase, not the frame.  If the bike is left to sit for more than a week, oil will migrate back to the sump from the "tank" in enough quantity to lower the level off the bottom of the dip stick.  Until you open it up, you won't know how much oil is actually in it, but the engine is quite capable of surviving with only half its normal oil amount.


The most likely causes of the engine being "seized" are failures of the rod big end bearing, broken valves on top of the piston, and seized camshafts.  Piston seizures are quite rare.

Sounds like you unscrewed the oil fill cap/where you pour in the oil and hence no dip stick.  On the 06 the dipstick/cap is in front of the engine on the shifter side. As gray said unless the bike is run/warmed up the cold dipstick check is not worth much- could likely read nothing.

Google 06 yz450 oil dispstick for what it should look like.  Little black knob thingy


As everyone else replied if the engine is seized your likely looking at a few thousand to make it run.  You would be better off buying a running bike versus some one elses junk.  Say $2000 in parts and repairs, plus the $800 to buy it, you could easily get a running 06 for that amount.

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