Topic: CB750 Airfilter box missing gasket

[Hop on a Honda]

Hi Guys, some time ago some attenting getting master mechanic mentioned that there is a rubber gasket in between the upper and lower half of the airfilter assy. Me thinks I have never seen one. so it dawns on me that mine is missing as the two halves do not seem to be seated correctly.
Sure enough its missing but its the top half which holds the rubber gasket. Invariably its almost impossible for the average two handed spanner wanker to get it in with out allowing it to drop out.
Answer- pull the whole assy out and glue it in carefully clean the filter properly and re assemble the whole lot and some how get it back in so as the four rubbers mate up properly with the bell housings of the four carbies and then pray that the four rubber joining gromets manage to actually go on.
Mine were as hard as a honeymooners dick.
Boiling water seems to be the only answer to make the rubbers more subtle.
Any clues as to make them pliable again?
Dave Australia
PS it idles now!!

[Honda CBer]

WD-40

[ofreen]

The best thing to do is buy new carb to airbox rubbers.  I replaced mine last year.  They were also hard as a rock, but I can't complain since they were 30 years old.  New ones will make it a lot easier to install the airbox and, more importantly, they will seal better.

[Hop on a Honda]

I believe your right The rubber seal is every thing when it comes to vaccume and carby performance.

The best thing to do is buy new carb to airbox rubbers. I replaced mine last year. They were also hard as a rock, but I can't complain since they were 30 years old. New ones will make it a lot easier to install the airbox and, more importantly, they will seal better.
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Dave

[jdpas29]

i used some thick cushiony weather stripping cut into pieces to make the shape around the joint between the two pieces of the airbox.    it seals up super tight and does the job.

[Raul CB750K1]

I had a hard time putting it back, and I remember I even openen a thread about it in the old forum. If I would have to do it again, provided that there is no reason to open those two halves, I would seal the joint with silicone permanently. Regarding the intake rubbers, I also bought new ones as the old ones were beyond restoration (they cracked when trying to ply).


Raul

[Hop on a Honda]

i used some thick cushiony weather stripping cut into pieces to make the shape around the joint between the two pieces of the airbox.    it seals up super tight and does the job.

I like the idea, maybe some 2MM glass weather seal maybe the go.
The super Locktite glue works excellent on the ends permanent joint
Great ideas.
The tubes here in Australia cost A$13.50 Inc GST (EA)
Dave
Australia.
FYI Freezing cold and wet.(Unusuall you ask?!)

[BobbyR]

I bought a new set of intake rubber from MReick, price was good and man what a difference in how easy it was to install the carbs, and she runs much better. I had to lean the carbs out since they were adjusted for the old leaky hard ones.