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danzick

yfz piston in a yz?

6 posts in this topic

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.

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

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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.

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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:

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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.

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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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