1975 CB750 Airbox access and filter change. HELP!

[Bubbafunk32]

Hello,
Is there a trick to getting the dang airbox open so I can check the airfilter on my bike?
I can't seem to find any info on how to open the thing up to change/check the airfilter!
any info would be great!

[CB750Winger]

  There should be two thumb screws under the bottom of airbox. They don't come all the way out but when you get them far enough out, the bottom half of the airbox drops down and remove the filter.  Paul

[Bubbafunk32]

No thumb screws. There are two bolts on top? I was told to loosen these to get the box to come down on another thead.
THanks for the reply.

[Re-run]

NO there are no thumb screws. The nuts sit in a recessed area at the bottom of the filter housing. So on the 2 top bolt heads, use a 10 mm wrench and loosen things up. Be careful as many have stripped out the nut housing on the bottom. Drop the bottom and it will slide out to the left or right but left seems easier.
When you go to tighten, do not over tighten. This where people go wrong. Just go hand tight and that should be good.

[Automagic]

I didn't know there were differences from the early 70's up, but my '77 CB750 has the two bolts from the top that hold up the divider between the top and bottom airbox, these two bolts extend past the divider with exposed threads, and the lower part with the filter is held up with 2 long female threaded bolts, accessible ,and removable from the bottom.

[Bubbafunk32]

Thanks!
It seems so simple now!

[Bubbafunk32]

Thanks!
It seems so simple now!

[Re-run]

Most likely your airbox got stripped out by the previous owner and that was his way of fixing it. The PO of my bike did the same with one side. He welded a nut to the bottom for a wrench. From my understanding, ALL the cb750 sohc models used the same method of closing the airbox.

[Automagic]

No, it's all stock and original.

http://hondaparts-direct.com/fiche_section_detail.asp?section=125256&category=Motorcycles&make=Honda&year=1977&fveh=2985

#33 is the bolt from the top, #16 is the female threaded bolt from the bottom.

[Re-run]

Do you have the flat top airbox then? the one without the hose connector at the top?

[Automagic]

Mine is just like the microfische shows except my fitting for the hose faces forward and to the right. I guess that can be considered flat.

[Re-run]

Hmm. ok then, never seen one like that but then it is not like I was on honda's assembly line!

[CB750Winger]

  I guess my terminology was wrong, there are two wing nuts on the bottom half of the air box. Screw them out and the bottom half of the airbox will drop right out. No need to do anything to the top. This is OEM stock for the 75 K.