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Author Topic: '78 750F Airbox removal  (Read 1142 times)

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Offline desertrefugee

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'78 750F Airbox removal
« on: November 25, 2019, 07:47:57 PM »
I am humbled.  I am embarrassed. I am about to throw a pry bar through my Polk Audio shop speakers.

I am not a rookie and have run into tough cookies before, but there has GOT to be a secret trick that allows one to extricate these danged airboxes.  What the heck am I missing?  There is no space to move in there.  It spent some time in the Arizona sun and is probably brittle.  I don't want to crack it either...

Somebody throw a broke down old hillbilly a bone.  Please.
« Last Edit: November 25, 2019, 08:00:14 PM by desertrefugee »
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'86 Vmax, '83 ZN1300, '78 GL1000, '75 CB750 K5, '78 F4

Offline 34barab

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Re: '78 750F Airbox removal
« Reply #1 on: November 25, 2019, 08:01:45 PM »
The stock airbox is two piece - top is bolted to the frame and bottom half is attached to the top with vertical bolts through the bottom.  This forum has a CB750F manual supplement under "manuals and technical documents".  Hope this helps.
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Offline 2wheels

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Re: '78 750F Airbox removal
« Reply #2 on: November 26, 2019, 11:21:33 AM »
There are 2 bolts on the top of the air box, 10mm wrench.
And sometimes you turn them and nothing happens.  Because the nuts, that are molded into the plastic at the bottom of the air box are slipping.
When this happens you take your dremel tool with a cut off wheel and notch the bottom nuts.  That allows you to put a slot screwdriver on the bottom nut to hold it.  While turning the top bolt.
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1970 CB750 K0 (I can't believe I tossed my duck tail seat in the trash 30 years ago)

Offline madmtnmotors

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Re: '78 750F Airbox removal
« Reply #3 on: November 26, 2019, 01:43:38 PM »
Quote from: 2wheels on November 26, 2019, 11:21:33 AM
There are 2 bolts on the top of the air box, 10mm wrench.
And sometimes you turn them and nothing happens.  Because the nuts, that are molded into the plastic at the bottom of the air box are slipping.
When this happens you take your dremel tool with a cut off wheel and notch the bottom nuts.  That allows you to put a slot screwdriver on the bottom nut to hold it.  While turning the top bolt.

This.

Leave the upper half bolted to the frame and remove the lower half. Then remove the upper half. The lower half is easier to remove to the right (towards kickstarter).

EZPZ  8)
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Offline ekpent

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Re: '78 750F Airbox removal
« Reply #4 on: November 26, 2019, 04:29:00 PM »
The 750 air box is the easiest air box to deal with then about any cycle I have owned. Once you split it into 2 pieces you will see.
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Offline desertrefugee

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Re: '78 750F Airbox removal
« Reply #5 on: November 26, 2019, 05:59:48 PM »
Thanks guys.  I had the bike back in a corner - and my eyes aren't what they once were.  As it happens, the vertical bolts were spinning as noted above.  I didn't realize the construction - I kinda thought they went into a captive insert.   

Appreciate the help!
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'86 Vmax, '83 ZN1300, '78 GL1000, '75 CB750 K5, '78 F4

Offline ekpent

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Re: '78 750F Airbox removal
« Reply #6 on: November 26, 2019, 06:41:37 PM »
 The older 750 airboxes were foolproof as they had a wingnut affair at the bottom that you loosen where the newer ones have that captive nut and open differently. A heat gun can help out the old rubber and soften it when mounting the air box or getting the carbs off those rock hard rubber manifolds if your going in that deep. Have fun !!.
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Offline desertrefugee

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Re: '78 750F Airbox removal
« Reply #7 on: November 27, 2019, 04:45:03 AM »
Uh, yeah.  I'll be going in pretty deep on this one...

(Thanks again for the sanity check)
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'86 Vmax, '83 ZN1300, '78 GL1000, '75 CB750 K5, '78 F4

Offline Magpie

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Re: '78 750F Airbox removal
« Reply #8 on: November 27, 2019, 11:40:05 AM »
You're not alone on this one. It took me a long time to figure how to get the airbox of my 77F.  ;D  Cliff.
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Offline Frank Rodgers

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Re: '78 750F Airbox removal
« Reply #9 on: November 30, 2019, 09:10:10 AM »
Took me a beer or 2 to figure it out. Does anyone have an extra hex bolt that goes in the bottom of the 77/78 air box? If so let me know. Gladly pay.
Thanks
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