Install 2007 Wr450 header pipe and silencer on 2003 Wr450?
Posted February 01, 2014 - 03:51 PM
If I just use the 2007 header pipe will it bolt up on the 2003 and work with the stock 2003 silencer? I have read some posts that say the 2007 header pipe may be too large to fit the stock 2003 silencer but I wasn't 100% sure if they were referring to the WR or YZ header pipes.
The reason I am doing this is because my titanium header pipe is crushed on my 2003 WR450 (it was that way when I bought it). I have access to a 2007 WR450 header pipe and stock silencer (if needed). If I can make it work I would like to use the 2007 silencer since my 2003 silencer doesn't have the insert to make it quieter.
I don't post on forums much but I really enjoy reading the posts on Thumpertalk. This is a great site! Thank you for any replies!
Posted February 01, 2014 - 04:05 PM
I was told by one of the better-informed posters here that it would work -- but will "stick out" further from the engine than the original head pipe.
One thing you should know: There are people who swear by filling a badly dented pipe with water and freezing it in the refridgerator to pop out the dents. Have no idea if this is true -- but there is a thread somewhere on this site (don't think it was on this particular WR forum) whose author swears it has worked for him numerous times.
There is a stock head pipe on ebay from a motorcycle salvage guy -- but it is already dented.
Posted February 01, 2014 - 06:14 PM
You can remove any dent, not matter how 'creased' with the freezer method.
Posted February 02, 2014 - 08:23 AM
Posted February 02, 2014 - 08:58 AM
Posted February 09, 2014 - 06:39 PM
Edited by WasatchRider, February 09, 2014 - 06:45 PM.
Posted February 10, 2014 - 08:28 AM
Here is a picture of the 2007 WR450 header pipe I installed on my 2003 WR450 with the stock silencer. The header pipe maybe sticks out a little farther but not too bad. It is a little loose at the header pipe to silencer sleeve connection so I might need a thicker gasket. Overall seems to work pretty good.20140208_214827.jpg
It is loose because the 2007-up header pipe is smaller diameter than the 2003 WR450 pipe.
So while you now have a straight pipe with no dents in it you have hurt the performance more than if you
had left the dented pipe on the bike.
You should look for a pipe that will have the proper diameter to mate with the silencer. 2003-4 WR450
and 2003-5 YZ450 are the same pipe. Also if that is the stock 2003 WR450 silencer it is crap and I
would dump it.