yfz piston in a yz?

got a yz450f, and i found some good deals on a high compression gytr piston but it says its for a yfz. i kinda figured the yfz and the yz were mostly the same accept some head parts and the bottom case. but it could be that the stroke is different also.

The '04 YFZ450 was a 439cc engine with a shorter stroke. The piston is different

well the piston is the same diameter right? just the shorter stroke makes it only a 439 im hopping or else i better get a big bore lol. oh and what is a good piston? should i just go with he stock one? ive heard the stock 04s had a pretty decent power plant from stock. one more thing, i need some new o rings for the oil lines going from the frame to the block, can i just get those at ace or something or does that need to be a yamaha part.

yfz pistons have a bigger wrist pin. 20mm i believe.

a common mod the quad guys do is a WR crank conversion because the piston is stronger :smirk:

well the piston is the same diameter right? just the shorter stroke makes it only a 439 im hopping or else i better get a big bore lol. oh and what is a good piston? should i just go with he stock one? ive heard the stock 04s had a pretty decent power plant from stock. one more thing, i need some new o rings for the oil lines going from the frame to the block, can i just get those at ace or something or does that need to be a yamaha part.
Let me say that more plainly: The piston from an '08 or earlier YFZ won't fit.

yeah, im not worried about it fitting anymore, i realize it wont work. now im just making sure the stock one is the right choice before i go buy one. i do mostly mountain riding, and like 5 dunes trips a year where i need good power for racing people up choke cherry in st Anthony Idaho. no mx racing.

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