Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: AndyD on May 17, 2020, 07:29:16 PM

Title: Airbox
Post by: AndyD on May 17, 2020, 07:29:16 PM

Softened the rubbers and 'forced' the airbox and carbs onto the bike to check she runs but not happy how things fitted so looking to sort this.
The rubbers to the head seem fine so I think I'll leave these (wintergreen softened them really well and have new O rings ).

The airbox and rubbers to the carbs are a different story!
Rubbers softened up OK but are a bit beaten up so will be replaced.
Fitting the carbs the rubbers just wouldn't go over the carb stubs fully so for testing fixed these 'just' onto the stubs.
Even with the rubbers short on the stubs (middle two especially) the joint to the filter box just seems too short - if I pull it back the carb rubbers don't reach.
Any idea if there were different airboxes / rubbers which could have been mixed up or is this maybe that the airbox is misshaped.
DSS have the airbox and rubbers in stock but I don't want to buy one if the same problem is likely.

Cheers,
Andy

Title: Re: Airbox
Post by: Nurse Julie on May 17, 2020, 07:56:23 PM

The air boxes tend to sink, especially in the middle, harden up and stay that way, that's why your middle 2 rubbers seem too short.

Title: Re: Airbox
Post by: Oggie400F on May 17, 2020, 09:24:10 PM

400fourbits has a couple of air boxes on his website if that is of help.

Title: Re: Airbox
Post by: AndyD on May 21, 2020, 03:21:32 PM

Thanks,
I've got a new airbox and rubbers from DSS as I think the old one was indeed a bit deformed and knackered.
Preparing to re-fit the carbs and have a few questions to make sure I don't get anything wrong...
Inside the airbox, I wanted to check which way round the rubber / sleeve connector bits fit - attached photo shows the bits I mean - the oval rubber and galvanised 'sleeve'.
[attach=1]
Also, I noticed in the Haynes manual it says to remove this galv sleeve, then the airbox and finally the carbs themselves in the dismantling section - is that what people do and if so is fitting a reversal of this, i.e. fit the carbs to the engine stubs, then squeeze the airbox in and connect up?
Cheers,
Andy

Title: Re: Airbox
Post by: philcarroll_1985 on August 09, 2020, 09:26:18 AM

I've read on another forum that one tip for refitting the airbox rubbers better onto the carbs is to stuff a push bike tyre inner tube into the air box and start pumping it up until it expands the airbox. I haven't tried it yet but sounds like a good plan

Sent from my VOG-L09 using Tapatalk

Title: Re: Airbox
Post by: Nurse Julie on August 09, 2020, 10:10:16 AM

Quote from: philcarroll_1985 on August 09, 2020, 09:26:18 AM

I've read on another forum that one tip for refitting the airbox rubbers better onto the carbs is to stuff a push bike tyre inner tube into the air box and start pumping it up until it expands the airbox. I haven't tried it yet but sounds like a good plan

Sent from my VOG-L09 using Tapatalk

Nope, can't get my head around that 🤔🤔🤔 unless they mean the tube just pushes the front of the airbox out due to it being the usual concave shape after many years.

Title: Re: Airbox
Post by: philcarroll_1985 on August 09, 2020, 10:34:40 AM

Quote from: Nurse Julie on August 09, 2020, 10:10:16 AM

Quote from: philcarroll_1985 on August 09, 2020, 09:26:18 AM

I've read on another forum that one tip for refitting the airbox rubbers better onto the carbs is to stuff a push bike tyre inner tube into the air box and start pumping it up until it expands the airbox. I haven't tried it yet but sounds like a good plan

Sent from my VOG-L09 using Tapatalk

Nope, can't get my head around that unless they mean the tube just pushes the front of the airbox out due to it being the usual concave shape after many years.

That exactly it

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Title: Re: Airbox
Post by: McCabe-Thiele (Ted) on August 09, 2020, 03:56:52 PM

I've had exactly the same issue doing a preliminary fitting of the air box . I've order some new rubbers for the airbox to carbs as they were in poor condition. I like the idea of inflating a small inner tube the push out the air box - I'm going to try that for sure it will save some money on the airbox replacement if it works.

Title: Re: Airbox
Post by: Nurse Julie on August 09, 2020, 05:47:44 PM

Well, when I have to remove and refit Hetties carbs next, I will consider trying that. I usually leave the air chamber in the sun, or on a radiator in the winter, to supple it up a bit, fit it to the bike and then push a big wooden spoon down through the air filter box and through to the chamber to give it a little help to push the rubbers on to the carbs.

Title: Re: Airbox
Post by: robvangulik on August 10, 2020, 11:04:56 AM

I always put the airchamber on the carbs first, and then put the complete assembly on the bike, bit of a squeeze, but at least I am sure that the chamber is mounted right, without edges and spaces on the carbs. Posted it before, see if I can find it...

http://www.sohc.co.uk/index.php/topic,16999.msg145183.html#msg145183