will 07 YZ250 filter cage fit 07 YZ450f?

[cnorton]

just wondering if the 07 YZ250 smoker filter cage will fit into the 07 YZ450 to eliminate the backfire screen? Does anyone know? This is my first YZ450. Thanks.

[Markopolo400]

Yes it will fit.

[grayracer513]

Sure. It will fit. But why? ?

[cnorton]

just wondering if it is worth running a cage without a backfire screen? is there any noticable difference?

[grayracer513]

Not according to dyno testing done on Doug Henry's SM YZ450 in '04. They tried a variety of different air box setups, and the removal of the screen made no detectable difference. The thing is that the best oiled foam filters are more restrictive that the screen is, so the screen is not an effective air flow limiter within the intake system on your bike.

[Ga426owner]

if you do this - make sure you get a fireproof filter - Twin Air

[cnorton]

just wondering if it is worth running a cage without a backfire screen? is there any noticable difference?

Not according to dyno testing done on Doug Henry's SM YZ450 in '04. They tried a variety of different air box setups, and the removal of the screen made no detectable difference. The thing is that the best oiled foam filters are more restrictive that the screen is, so the screen is not an effective air flow limiter within the intake system on your bike.

Makes sense, so what air filters flow best and how much should a person be oiling them without having the chance of dirt infiltration. I use twin air filters with no toil and try to squeeze them out after oiling as much as possible, I do believe that an over oiled filter will restrict air flow.

[grayracer513]

Most of the better filters (Twin Air, White, etc., flow about the same. I don't have any test results at hand to refer to as to one being better than the other, but it's never made a difference I've been able to notice.

The filter, in order to protect the engine, has to be oiled so that every cubic centimeter, not every square centimeter, of the foam media is coated with oil. The only good way to ensure this is to apply an excess, work it thoroughly through the element, and squeeze off what you can. If you actually leave an excess in the filter, it will usually "drain" to the bottom edge as it dries.

[KJ790]

I have run two stroke cages in all of my fourstrokes for years just b/c I think they are easier to install than cages with a screen. I can wrap my fingers inside when putting the screen into the filter. The bike doesn't run any different, but I think it's worth it for me just for the ease of changing the filter.