Topic: Honda CB550 Air Filter

[bryanj]

Koni dont exist anymore, its now Ikon and Australian

[Deltarider]

@ Kyle Who or what am I parroting? It's my habit to parrot only my own nonsense. But maybe, I've missed something. Is your CB750 by any chance not original in the frame/swingarm department? I vaguely remember a special thread. I hope you haven't destroyed it. Others may chime in to correct me.
@ Bryanj Koni is alive and kicking. They have only sold the motorcycle shocks division to an Australian company and the latter has renamed the shocks IKON. AFAIK they're identical to the original Konis.

[bryanj]

The only Konis we talk about are motorcycle and Ikon, whilst still making  shocks do not make spares that fit the older Koni shocks and limited for all Koni.
Big original thing for Konis was that although expensive all parts were available and they were easily rebuildable and adjustable

[Deltarider]

The only Konis we talk about are motorcycle and Ikon, whilst still making  shocks do not make spares that fit the older Koni shocks and limited for all Koni.
Big original thing for Konis was that although expensive all parts were available and they were easily rebuildable and adjustable

Koni's service was great and well known.

[Stev-o]

It's my habit to parrot only my own nonsense.

Quote of the day!!!!!

[Deltarider]

It's my habit to parrot only my own nonsense.

Quote of the day!!!!!

Too much honour, Steve, too much honour.

[Deltarider]

*Some performance could be gained when the engine gets vacuum... more vacuum results in less push-pull air movement underneath the pistons and less drag on the crank

I know the theory. In practice this bracket https://www.cmsnl.com/honda-cb500k2-general-export_model50441/guide-breather_90514323610/ fitted exclusively on the CB500K2-ED, -F, -G will result in a slight underpressure (riding wind), provided you will fit it right.

[kyle750]

A quick note on my CB750 Air Filter Box

Removing the old air filter took only 2 minutes.  Untightened the 2 lower wing nuts, the lower half dropped down, removed the old air filter, and cleaned around the inner box.  Simple and Easy!

So I thought reinstalling might take a little longer but "no more than 5 minutes".  Wrong - 2 hours it took us  The top edge of the lower black plastic box was not installed correctly into the groove of the upper box and it was permanently bent inwards in the front.  It took me over an hour and many attempts to realize something was wrong - looking closer you could see it was not straight.  I am quessing that someone just carelessly tightened it up but never seated it correctly.  It was now permanently warped and would not fit back into the groove. Also a possibility is that it just popped out over time.

Frustrating the number of attempts.  Finally we heated the lower box up and tried to bend out the warped front edge. Then I installed the front edge into the upper groove first and held upward pressure from below at each corner carefully keeping it in place while Kannika threaded the wing nut bolts from below.  She then tightened each bolt a few turns at a time then moved to the other side.  As I seated the front edge first with continuous pressure it stayed in the groove and with gradual tightening the rest of the lower box slowly seated correctly into the upper box.  Unbelievable!

[kyle750]

Originally I thought it might take 20 minutes to change both the air filters on the CB550 and CB750

[kyle750]

Many thanks for the breather bracket information. The photo of the installed bracket was very dark so I increased brightness so it can be seen a little better.   Photos attached.

Although useful I can't see how this bracket would be essential. 

[BenelliSEI]

Try putting the deformed part of the air box in boiling water for a few minutes and then insert a brace to push it back (or a bit further) while it cools. Works for me.

[kyle750]

Try putting the deformed part of the air box in boiling water for a few minutes and then insert a brace to push it back (or a bit further) while it cools. Works for me.

I wish I had talked to you before the struggle. Thanks Mate for the expert advice.   Boiling water would have been much better than baking in the hot sun.  While baking in the sun I did use a wood brace to push it back but I was afraid it would break the plastic so I did not push it back far enough. Once I released the brace it quickly reverted to its old deformed shape.   It was a real struggle but it's in  . . . and more importantly it's in correctly! 

[Deltarider]

Many thanks for the breather bracket information. The photo of the installed bracket was very dark so I increased brightness so it can be seen a little better.   Photos attached.

Although useful I can't see how this bracket would be essential. 

The bracket is just an example of Japanese tidiness. It's this tidiness that made these bikes so reliable. The bracket in that picture is the one for the 500 and not for the 550. The CB550K2 exclusively had a smaller one.

[kyle750]

Many thanks for the breather bracket information. The photo of the installed bracket was very dark so I increased brightness so it can be seen a little better.   Photos attached.

Although useful I can't see how this bracket would be essential. 

The bracket is just an example of Japanese tidiness. It's this tidiness that made these bikes so reliable. The bracket in that picture is the one for the 500 and not for the 550. The CB550K2 exclusively had a smaller one.

The CB500 breather bracket you show is to attach the end of the breather hose so oil vapors are vented to the atmosphere?  Is this correct?  Since the CB550 had a PCV system for venting the vapors with a breather hose connected directly to the air box and not the atmosphere why would the CB550 originally have had a breather bracket at all? 

[jonda500]

I read that some 550's had a small tube with a squeeze valve there to drain the condensation trap in the bottom of the air filter housing?
John

[kyle750]

I read that some 550's had a small tube with a squeeze valve there to drain the condensation trap in the bottom of the air filter housing?
John

Thanks mate.  Looking for a valve now.  Very hard to see the underside of the air filter box  I w̶a̶n̶t̶  (need) a motorcycle lift 

[HondaMan]

I read that some 550's had a small tube with a squeeze valve there to drain the condensation trap in the bottom of the air filter housing?
John

Yep. I saw one of those once, but it was on a visiting Brit's bike!

[Deltarider]

I read that some 550's had a small tube with a squeeze valve there to drain the condensation trap in the bottom of the air filter housing?
John

Correct. And here is the drain tube of the plenum. https://www.cmsnl.com/honda-cb500k2-general-export_model50441/tube-breather_17335323000/
The end with the foam filter inside, is to connect to the plenum.

[kyle750]

Let me see if I have this correct    The Honda CB550 has a a PCV system with a breather hose connecting the valve cover to the air filter box to release oil vapors into the air box to be filtered by the air filter.  The oil vapors introduced into the air filter system create additional water/condensation that collects at the bottom of the air filter box.  This must occur at or around the removable tube mechanism as this mechanism sits at the very bottom/lowest point in the air filter box?     And there is another hose leading from the bottom of the air filter box to expel/drain any condensation collecting from inside and sitting at the bottom of the air filter box? 

[Little_Phil]

Air from the breather enters the hole in the bottom of the filter casing and has to pass through a sponge filter and enters the inside of the filter through a short pipe that protrudes up into the filter. The sponge is supposed to separate any oily muck and drain it out the tube hanging underneath that has the squeeze tube ending and is NLA.
https://www.cmsnl.com/honda-cb550f1-super-sport-550-four-1976-england_model17113/tube-assy-drain_17358374000/

Set up on the F1:
https://images.cmsnl.com/img/partslists/honda-cb550f1-super-sport-550-four-1976-england-air-cleaner_big00026127f15_f0f5.gif

Honda not very successfully played around with the length of the steel tube that passes up the inside of the filter to try to stop the filter getting saturated with oily moisture.

[kyle750]

Air from the breather enters the hole in the bottom of the filter casing and has to pass through a sponge filter and enters the inside of the filter through a short pipe that protrudes up into the filter. The sponge is supposed to separate any oily muck and drain it out the tube hanging underneath that has the squeeze tube ending and is NLA.
https://www.cmsnl.com/honda-cb550f1-super-sport-550-four-1976-england_model17113/tube-assy-drain_17358374000/

Set up on the F1:
https://images.cmsnl.com/img/partslists/honda-cb550f1-super-sport-550-four-1976-england-air-cleaner_big00026127f15_f0f5.gif

Honda not very successfully played around with the length of the steel tube that passes up the inside of the filter to try to stop the filter getting saturated with oily moisture.

An EXCELLENT explanation and very helpful diagram.  Thank You.  My CB550 had the tube mechanism in place (19) but was missing items 20, 21, 22, and 23 and based on this diagram I am quessing oily muck would collect in item 22 (whatever that is?)

Basically a mini-scrubber system in an attempt to filter the vapors of oil, muck, and water before the dirty vapor reaches the air filter?

[bryanj]

Item 22 is like a steel sump pan withmesh cover but big round holes, the part above it is a foam filter.
All of it is supposed to stop oily crud getting into the paper filter and ruining it but it dont work

[kyle750]

Item 22 is like a steel sump pan withmesh cover but big round holes, the part above it is a foam filter.
All of it is supposed to stop oily crud getting into the paper filter and ruining it but it dont work

Perfect timing as I found a photo of item 22 just as you posted your comment.  I am quessing 21 is a foam filter and 20 is an outer frame to hold the foam and this is placed under the tube mechanism.

[kyle750]

Does anyone own a CB550 with the original PCV setup including all the individual components? And does it work?

[jlh3rd]

yep, I do...'75 550F, unrestored, original.