Topic: 1977 750 Supersport Air Box

[reliv77]

Looking at changing my Air Filter on my 1977 750F Supersport (first time / new bike). The Clymer Manual says to loosen the Wing Nuts on the Bottom of the Air Box. Got None. Almost appears they where broken off if there where some. Is this common to have them break off? What might be holding the Bottom of the Air Box to the Top of the Air Box?

[2wheels]

Clymer is wrong for your bike.
You loosen the 2 bolts (10 mm wrench) on the top of the air box.
Your problem will be the nuts (the parts you think are broken wing nuts) will spin in the plastic.
If you get there I have a easy solution for that.

[Bailgang]

Look at the bolts that secure the air box to the frame (the one going into the sides) then look at the bolt near them that's going straight down. It's the bolts going straight down that you want to loosen. The nut at the bottom is recessed into the bottom of the air box and is molded around the hex of the nut to keep it from spinning while you loosen the bolt. As you loosen the bolt the nut which is more like a threaded sleeve (can't think of a better way to describe it) will drop out the bottom.

[reliv77]

I see the Bolts you are talking about. There are the Bolts that hold the Air Box to the Frame. And then there are the Bolts on Top of the Air Box. When I turn the Bolts on Top of the Air Box, they just turn and turn. I can feel the nuts at the bottom that are Recessed into the Bottom of the Air Box spinning as I turn the Top Bolts. Nothing loosening.

[2wheels]

I see the Bolts you are talking about. There are the Bolts that hold the Air Box to the Frame. And then there are the Bolts on Top of the Air Box. When I turn the Bolts on Top of the Air Box, they just turn and turn. I can feel the nuts at the bottom that are Recessed into the Bottom of the Air Box spinning as I turn the Top Bolts. Nothing loosening.

So that is pretty much exactly what happen to me.
My fix was to use a dremmel tool with a cut off wheel.  I used the tool to cut a slot in each nut so a slot screw driver can hold the nut still. 

[reliv77]

I assume you are talking about the the Nut on the bottom of the Air Box to cut the Slot in. Then from then on you would use a Screw Diver on the Bottom of the Air Box and the Wrench on Top of the Air Box to Change the Filter? Or is there a way to "Fix " the nut in place?

[madmtnmotors]

I assume you are talking about the the Nut on the bottom of the Air Box to cut the Slot in. Then from then on you would use a Screw Diver on the Bottom of the Air Box and the Wrench on Top of the Air Box to Change the Filter? Or is there a way to "Fix " the nut in place?

Sounds like you understand correctly. 2wheels suggestion is the neatest/cleanest solution to this issue. Any airbox I touch gets this treatment, even those without any problems "just in case". The only thing "fixing" the nut in place is the plastic airbox. Once the plastic gives way you need to establish a means to hold it with a tool. Since it finishes flush to the surrounding plastic, the slot for a screwdriver works well.

[2wheels]

See picture.
I used a screw driver bit from my impact driver.  Just hold the bit with vice grips or wrench.  There is not much room under there.

[KRONUS0100]

i hold the ones on my bike in place with black rtv.  havent had issues in couple years

[reliv77]

Sorry, What is "black rtv" ?

[madmtnmotors]

Sorry, What is "black rtv" ?

That would be "silly-cone". I would think for silicone to work you would have to get the airbox apart first, then imbed the bottom fastener with said silicone. Not sure if just a surface application of silicone would hold much...

[Black 750K8]

I used epoxy after I used a dremmel to make room. But the screw driver method is a lot better if mine comes loose again that is what I will do.