Topic: adhesive on airbox boots?

[gmonkey]

Do the boots that go between the carbs and plenum and the gasket that goes between the plenum and air box just get stuck in their respective openings dry or is there some kind of lube or adhesive?  I thought they just get stuck in but there's some residue stuck on around the holes on the plenum.

[kvallelunga]

I use a very light coating of K&N air filter base grease to make the carbs slide into the boots easier and the air box boots too.

[Gordon]

Do the boots that go between the carbs and plenum and the gasket that goes between the plenum and air box just get stuck in their respective openings dry or is there some kind of lube or adhesive?  I thought they just get stuck in but there's some residue stuck on around the holes on the plenum.

The parts you're talking about ( I think you're talking about where the boots and airbox meet) are supposed to seal properly without any kind of additional sealant.  However, after a few decades they tend to shrink and harden, so if yours are the original parts they may need some assistance to make a good seal, which may be why a PO used some.  If you've never held brand new air box boots in your hand, you'll be really surprised when you do at just how soft they're actually supposed to be. 

Kvall,

I think you may be thinking of slightly different parts than what gmonkey is asking about.  When fitting carbs to old rubber boots it definitely helps to lube up the contact surfaces to get things to slide together smoothly. 

[SohRon]

Hmmmm... I bought two new air boxes (chambers) from Honda, and both have the rubber "velocity stacks" attached to them with an adhesive sealant. Apparently this is unnecessary? I thought that this was why the boots (stacks) weren't available as a seperate item, and the airchamber came only as an assembly?

[TwoTired]

Hmmmm... I bought two new air boxes (chambers) from Honda, and both have the rubber "velocity stacks" attached to them with an adhesive sealant. Apparently this is unnecessary? I thought that this was why the boots (stacks) weren't available as a seperate item, and the airchamber came only as an assembly?

You are correct.  The air plenum and boots were only available as an assembly from Honda, and they were indeed glued together with some sort of contact cement or rubber adhesive.  They were never expected to be separated.  I think this is partly because without the glue the boots can rotate out of correct alignment.

However, I think David Silver Spared had some pattern boots made to replace the early model types.  If you have PD carbs on your bike, I don't think the proper boots are available as new.  Just used ones.

Cheers,

[SohRon]

without the glue the boots can rotate out of correct alignment.

...so, do you suggest that any loose or replacement boots should be glued down, or is it acceptable to leave them loose? Which, I think, was the OPs question.

It seems that, once the clamps are applied, the boots wouldn't be free to rotate out of  place... or is this merely a pre-assembly precaution to ensure the boots on one and four are correctly aligned?

[Gordon]

You are correct.  The air plenum and boots were only available as an assembly from Honda, and they were indeed glued together with some sort of contact cement or rubber adhesive.  They were never expected to be separated.  I think this is partly because without the glue the boots can rotate out of correct alignment.

Well, you learn something new every day.  I guess all the air box boots on all the sohc4's I've had were so old and shrunken that the glue had flaked away.  Sorry for the misinformation, gmonkey. 

[TwoTired]

without the glue the boots can rotate out of correct alignment.

...so, do you suggest that any loose or replacement boots should be glued down, or is it acceptable to leave them loose? Which, I think, was the OPs question.

It seems that, once the clamps are applied, the boots wouldn't be free to rotate out of  place... or is this merely a pre-assembly precaution to ensure the boots on one and four are correctly aligned?

It's probably not a requirement they be glued in.  It was probably a production/assembly speed aid, as the boot's all need to deflect when installing the carbs.  Gluing them in kept them in proper place during assembly.  They were quite soft when new and installing the carb bank likely knocked them out of the box fairly regularly on the production line without the glue.  Gluing them into one assembly saved time and allowed the installer some latitude with a rough installation.

Cheers,

[SohRon]

It's probably not a requirement they be glued in.  It was probably a production/assembly speed aid, as the boot's all need to deflect when installing the carbs.  Gluing them in kept them in proper place during assembly.  They were quite soft when new and installing the carb bank likely knocked them out of the box fairly regularly on the production line without the glue.  Gluing them into one assembly saved time and allowed the installer some latitude with a rough installation.

Thanks, TwoTired. If the adhesive is used by Honda only as an in-house assembly aid and serves no other purpose, then Gordon is absolutely correct; the only real concern (apparently) is that the boots aren't hard and shrunken and that they are aligned correctly during installation.

Sorry to have hijacked the thread, gmonkey, but this is a question I've had for a while, too!  Everybody learned something today!  

[TwoTired]

The boots do shrink with time.  You probably need to make a spot evaluation of how the boots seal against the plastic.  If loose, then the adhesive is probably indicated, just to help with the seal.  Also, it is not just the inner diameter that makes the seal, but the seating flanges as well.  Probably not critical, but something to consider.

Cheers,

[Popwood]

Air box boot proper alignment? I just bought a new set and installed as part of a carb clean up on '75 750K. They all four rather looked the same to me with the possible exception being the "accordian pleats" seemed to be slightly closer together on one side vs. the other. I just put them in and called it a day.

But after my carb cleaning the bike isn't running properly, but I'm going to post a list of what I did hoping to get some help.

[TwoTired]

The OP has a CB550F.  These have different inner/outer couplers and need alignment.  The diferrence is rather obscure since Honda did not sell these boots separately.  They were sold glued to the air plenum and offered only as an assembly.

[gmonkey]

Thanks for the info.  I think my boots are in good enough shape to seal especially under any serious vacuum.  Actually kind of surprising how soft and flexible the rubber was.  All the other rubber bits on the bike are pretty hard.

Surprised to hear the plenum and boots were installed as one unit.  Are they supposed to be attached to the carbs first and then go in together?  I had the carbs on first then put in the plenum then stuck the boots in.  The center 2 went in through the inside of the box. 

[TwoTired]

The plenum and filter box are assembled together (boots already installed) and allowed to sit loose in the frame, or pushed as far rearward as possible. (frame down tubes will block most movement)   The Front couplers are installed on the manifolds.
All the rear boot clamps are completely removed.
The carbs are pushed across the front couplers and the rear boots are deflected and gently massaged to allow carb bank movement, until they are aligned with the front couplers and pressed home.  Then the rear boot clamps are installed.  Then the filter box is bolted down.

If the rear boots are hardened the job is more difficult.  Silicone spray does help during carb installation, as does a right angle pick.