OK...DrD has responded to my e-mail inquiry:
Here's my e-mail message:
"Comments: I sent this same message to the Technical folks at Dubach Racing but never received a response. I purchased the DrD
stainless steal header w/ aluminum muffler for my 2007 Yamaha
WR450F. The fit and finish are great and the system works great on my bike. The problem is the bend in the header pipe cover the top bolt on the oil filter
cover making removal impossible without at least loosening the entire exhaust
system. The DrD header shape turns a simple oil and filter change into a much more complicated process since I now have to loosen the exhaust system in order to perform this frequent service task. I'm looking for some feedback from Dubach Racing addressing this issue. I tried repeatedly during installation to position the header to allow clearance but when the system is positioned and the bolts are torqued down...I could not make the header clear access to the bolt. Thank you for you timely response.
And here is Dubach's official response:
Unfortunately that is something you will run across with the YZ450F complete system. You do not have to completely remove the head pipe but you do have to loosen the bolts on the head pipe. Let me know if you have any question.
Dubach Racing Development
2038 Second St.
Norco, CA 92860
Toll Free: 877-DUBACH1 (3822241)
Translation: You're S.O.L
. Buyer beware
...If you purchase this excellent system know that you will have to either modify the top oil filter bolt by converting it to as stud and nut system or, you will have to loosen the exhaust system in order to swing the header pipe out of the way to access the top oil filter bolt.
IMO...this is a pain in the ass and a definite advantage to other aftermarket exhaust manufacturers against the DrD system. I really like my DrD system and I don't feel as though I've been ripped off...but I do feel Dubach Racing knew this would be an issue and deliberately chose to remain silent.
It certainly gives me something to think about the next time I decide to spend money on the Blue Beasty.
DrD...I give you a "D" for this.