Topic: K7 and K8 750 airbox again.

[beemerbum]

some time ago there was a discussion in re the part of the 77 and 78 airboxes ant the part called the "separator". After a member here turned me on to one for sale on Ebay, Iordered it immediately. I received some odd custom turn signals instead, which are totally useless and was told, upon my complaint, that the Honda part was no longer available.
The whole point here is the question of whether the rubber "gasket" part of this unit is necessary. The old one is useless, in spite its appearance in the photo. Has anyone run the bike without the rubber part? If so, what was the result.
The "separator" fits very snugly without the rubber.

[Kaze]

- You said the gasket was toast? If it's only a bit dried out, you might be able to get it to be a little more supple by rubbing it down with some silicone grease. If it's cut, you may be able to repair it with some liquid rubber gasket "goop" (not on the airbox of course).

- If your gasket is utter garbage, I would go to Home Depot and look for some rubber weather stripping that's about the right diameter, and use it rather than nothing (and rather than forking over $35 for a rubber airbox seal).

Just for reference, K models from 1972-1976 use part # 17221341000 for the rubber gasket.  It's not listed as a separate item for K7/K8, so I cannot compare to see if older models will fit or not.
K7 parts list:  https://www.cmsnl.com/honda-cb750k7-four-1977-usa_model495/partslist/F++15.html

[beemerbum]

Check Partzilla. It is listed as a separate part. It is Honda part # 17230-405-305, It appears to come with the rubber "gasket" attached. I'm trying to find out if its presence (the rubber part) is necessary for running. What is the effect of its absence.

I doubt that any weatherstripping from a hardware store would survive in an environment involving fuel.

[Kaze]

Black rubber of the same general diameter of the gasket. It's generally sold by the foot. (Not the foamy type that goes around door jambs)

[Kaze]

I went out and removed my K6 airbox and compared it with one from a K7, the K7 is a full 1/2" longer. (Not the gasket, but the whole box) So a K6 or older packing-gasket won't work.

[beemerbum]

Like many other diffrences between K6 and K7/K8. For some reason, the K7 left side upper motor mount is entirely different from K6 and K8. Go figure.

[beemerbum]

If I recall BenelliSEI, who owns both K7 and K8 750's spoke to the airbox business on those bikes

[Kaze]

I looked at my spare K7 airbox thinking I might offer you the gasket, but I'm sad to say that my gasket is gone too. Sorry I couldn't help more.

K6 vs K7/K8: I feel you. The list of K7/8 changes is mind-blowing. My current bike is 90% K6 with a K7 frame and rear end. But that left side, removable motor mount is apparently so that we can remove our engine from either side. K6 and older you sort of "had" to remove the engine from the right. I don't want to remove my engine anymore. It's heavy and I'm weaker than when I put it in.

[BenelliSEI]

I used something else for that gasket.  Maybe a very small diameter fuel line (like for a weed eater). I’ll have a look next time I am in the shop.

Re the removable LF engine mount, only on a K7; its purpose is a total mystery. You certainly can’t remove the engine from the left side. It does make tipping the engine forward slightly easier, but it still has to go right…….