yamaha 450 head swap

Does anyone have experience with interchangeability of 450 heads? i want to see what years and models i can search for the head swap. i have a 2005 wr450, could i use any 450 head? 2003 -2009 yz/wr/yfz block? i don't use the AIS system...and i will swap everything (valves, cams, etc) over. i tried to look up p/n unsuccessfully... :thumbsup:

I was woundering what the differece was between the wr and yz. is just cam timing or what. i looked up part #s on cams and they r the same as r the pistons. I know the wr has a six speed and a heavier flywheel. But what else is different.

a lot... from the wide ratio tranny to the cams with the compression release to the AIS system...never mind if you try to see the differences with the YFZ quad motor...

Well i was not sure i have a 2004 wr i just got and i was woundering. i was thinking about making it hit a little harder.

when u say ais system. what is that.

Does anyone have experience with interchangeability of 450 heads? i want to see what years and models i can search for the head swap. i have a 2005 wr450, could i use any 450 head? 2003 -2009 yz/wr/yfz block? i don't use the AIS system...and i will swap everything (valves, cams, etc) over. i tried to look up p/n unsuccessfully... :thumbsup:
Except for the AIS, heads from an '03-'05 YZ450, '03-'06 WR450, or '04-'08 YFZ450 Quad will fit.
I was woundering what the differece was between the wr and yz. is just cam timing or what. i looked up part #s on cams and they r the same as r the pistons. I know the wr has a six speed and a heavier flywheel. But what else is different.
The intake cams are the same on the earlier WR450's but the exhaust cams are different from YZ450 cams in all years, and therein lies the difference.
when u say ais system. what is that.

When you type "u", what is that?

Hey thanks for info. been out of dirt bikes for a while and just getting back into it. I traded my 92 KLR for my 04 WR 450. I liked my KLR but its no fun offroad.

thanks greyracer, the hard part begins...finding a reasonably priced used head that i can send out for a P & P before i take the bike apart to minimize downtime...

Just to be sure before to order parts.

I have wr450 2003, and definitely need a new head.

Does the head from 2005 will fit on 2003 WR450?

Can i use my cams from 2003 to a new 2005 head?

Does the top end gasket are the same, or will need 2005 gaskets?

Please advice. Thanks.

I believe any WR head from 2003 - 2006 will fit. In 2007 they changed the head and incorporated the cam oil feed line internally. Before that it was external. Not sure what year the YZ made the change. Possibly in 2006.

The 2003-2005 cams, valves, lifters, gaskets and etc. are the same part numbers.

I think the only deference is AIS system vacum port and lowered compression ratio.

Please someone to confirm.

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