Topic: Help picking out OEM air box for '74 CB550K

[CBGhia]

Ok, it looks like this filter will actually fit in there

UNI Two Stage Pod Filter (Straight Mount / 2-1/2" X 4) https://www.amazon.com/dp/B001A6RBA0/ref=cm_sw_r_cp_apa_i_7PX6Cb0938SVP

[uncle_fester]

I have a question related to the original post.

Just got my air box and am cleaning it up before install. There's two ports on it: one directly on the air box and another on the air filter plate.

Are these supposed to be connected to anything? If so, what needs to be attached here? I do not see any extra breather hoses under my seat. Confused....

[Scott S]

 The one on the filter holder is for the crankcase vent, on top of the valve cover.

 The one on the plenum is a drain, if the carbs ever overflowed. The stock hose reduces down to a smaller diameter and has a slit or "pooter" in in, so you can pinch it and drain the fuel. Just run a hose down behind the engine and put some foam in the end so that the air isn't unfiltered.  The stock hose is very hard to find.

[uncle_fester]

Thank you.

[uncle_fester]

I have (hopefully) one more question related to the original post.

To those of you who've used the filter adapter, did you change up your jetting or needle position at all, or keep it stock? I figured the K&N filter might have better air flow than stock, so going a little richer might be a good idea.

[CBGhia]

I have (hopefully) one more question related to the original post.

To those of you who've used the filter adapter, did you change up your jetting or needle position at all, or keep it stock? I figured the K&N filter might have better air flow than stock, so going a little richer might be a good idea.

On my 550 with a 650 cam, I was using 110 jets with the K&N.  I just put the same thing in my 500, but it's not ready for jet testing, yet.