Exhaust blocks oil filter cap on 06' WR450F

Hey all,

So i went to change my oil for the season start and i realised that the exhaust blocks one of the bolts on the oil filter cap.

Its a aftermarket yoshi, this is my first oil change on this bike since i bought it last year.

Here is a picture of it, the exhaust is unbolted as i was trying to see it i could re adjust it but no dice. But this is basically how it sits.

Im unsure if i can get this bolt out as i cant get a hex key in there and take the bolt out.


I have the same machine...steel framed 450. I looked at mine and there isn't a whole lot of clearance on it either...just enough to get the hex key in. It looks like you only need about 1/4 of an inch more and you would be good to go.

The parts diagram I looked at seems to show that the bracket on the header that bolts to the cylinder head, and the header itself are 1 piece...which means that you cannot rotate just the header and still have the bracket line up with the holes on the cylinder...but I may be wrong (hopefully).

The only suggestion I have..and you may have already done this so sorry if its no help.... is to loosen the two bolts holding the front of the header to the head itself...then loosen the clamp from the back of the header to the rear pipe and then try some fairly agressive wiggling up and down combined with twisting to see if you can get it to rotate/reposition just slightly higher up. Then hold it there and tighten everything back up.

Maybe you'll get lucky!!

Also..there seems to be a seam in the pipe just under the bottom of the rad. I do not have this on mine. Is that an actual "seam"...ie a location where one piece of pipe is just fitting inside the other and is just held there by pressure when all the screws are tightened??. If so you should be able to get the piece thats in the way to rotate "up" (make sure the header bracket to the rear pipe is loose) inside this piece and that would give you the clearance you need.

Good luck....sure makes for PITA filter changes the way it is.

I have tried to re locate it but once you tighten it back down it moves back, its a aftermarket pipe so its not perfect but the what the 2 pieces come together makes for VERY VERY little adjustment one its lose i can move it up and down out of the way kinda but i don't want to undo it then let it run to get oil moving then try and take the pipe off as it will be good and hot as it is only a single header. i find it kinda annoying as it takes me like 2 mins to take what i need off and out of the way on my street bike but then to turn around and have to disassemble everything to take the filter out on the dirt bike.

The biggest reason i want to figure it out is because i'm not looking at getting a new dirt bike any time soon and i don't have a need to mod this one like i did my street bike as i beat the hell out of my dirt bike so no point in putting any money into it other then to keep it running good.

oh and the bracket moves around on the header if i loosen it off and i can rotate the pipe but its that once i bolt the muffler and everything back up it sits back down in front of the bolt

That's a stupid design...

I can't tell how much room you have behind that pipe, but would replacing the bolt with a stud and nut allow you enought room to get the cover off? If so at least you won't have to deal with this BS each time. If the stud and nut works, just locktite the stud in place.

Another option 'might" be to grind an opening into the top bolt hole in the cover to create a "slot". That will only work if there isn't an issue with the seal on the mating surface. (make sure a replacement is available & affordable "just in case" it doesn't work out.) Then you can slide it in place. If this works you can just replace the socket cap screw with a hex cap screw, so you can turn it with a regular open end wrench.

I'll be changing my oil for the first time on my 08 tonight or in the morning, then I will be able to tell you better what will work.

Jeez, just change it to a hex head bolt......

Or throw a stock exhaust back on it. Mine is stock, and I have no problems doing an oil change. Maniac

The stud and nut thing could work but its teh fact that i wont have room to pull the bolt out in the first place.

I would put a stock pipe on but i do not have one as it came with aftermarket one.

Yes its a stupid design but if it were up even just a half inch it wouldnt be a problem.

Will have to take a better look next time im home.

Yeah...gotta think Maniac998 is right.

If you can't get it to move...put a stock exhaust on it.

Maybe you'll be able to just swap out the header and keep the rest of the exhaust.

Ill have to play around with it more, keeping this exhaust would be ideal as then i dont have to spend money, i guess that the fact that i only have to change the oil once (beginning) or twice (if i ride enough) that i can just let it run to warm up and wile its draining the oil i could unhook the header?

I just changed my oil a few minutes ago.

It looks like you need enough clearance to get the filter and cover aligned. I'm not sure you will have enough room to do that if you convert the bolt to a stud.

But it should not be too time consuming to just pull the head pipe each time. The manual says you only need to change the filter every fifth oil change, so that won't be very often.

EDIT: That last sentence is wrong. Need to change filter every other oil change.

Edited by GlennR



What about "hammering" a soft bulge in the header, so the screw can be reached, just a thought.

Regards Carsten

GlennR, This is what i was thinking, my only concern with it would be the head pipe getting a bit too hot?

hjorth, it would have to be a big dent to be able to do what you are thinking, i will probably just remove (lossen) the pipe when i need to change filter, if i come accross a stock one on kijiji or something i will possibly look at puting a stock one from a WR or a YZ on it.

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