Topic: Aitbox setup - tubes

[jensk]

I have just started my renovationsproject of an CB550K '77 that i bought 2 weeks ago.
t is currently equipped with separate airfilters directly connected to each carb. I have bought a used airbox. My problem right now is how to connect the hoses to the three studs on the airbox - se picture. I guess one is for connecting the ventilation of the crankbox but what is the other two for?

I have read the carb FAQ and understand that the '77 CB550K is somewhat different that the CB550Fand other SOHC/4's. Mine has a 4 into 1 exhaust. Will this be a problem regarding rejeting when installing the original aitbox. Any advice would be nice.
JK

[daz]

Hi JK, the 4 into 1 exhaust will work fine no rejetting needed. On the air box, the one at the bottom of the main air box is a drain, the one with an elbow goes to the top of the engine, the other one is a breather, hope this helps Darren

[daz]

sorry got the rejetting bit wrong, you will need to check jet sizes against factory fitted sizes,  if  you go back to the standard air box.
The 4 into 1 exhaust will work both ways, Daz

[scadaman29325]

Hi JK, the 4 into 1 exhaust will work fine no rejetting needed. On the air box, the one at the bottom of the main air box is a drain, the one with an elbow goes to the top of the engine, the other one is a breather, hope this helps Darren

...the one at the bottom of the main air box is a drain...
Is it a 'regular' hose or something special like it might pinch itself closed so it doesn't suck air past the filter?

...the one with an elbow goes to the top of the engine...
This one I think I got figured out.

...the other one is a breather...
Same question as the 'bottom' hose (who da, what da, where da).

Thanks, Phil

[Bodi]

The bottom tube is a water drain from the airbox, it should connect to a tube with a sort of one-way valve "mouth" molded on the end going down behind the engine.
The other two... one is to the engine vent at the top of the valvegear cover. There should be a fibre pad thingy sitting in the bottom recess of the filter housing to collect oil, the crankcase gas should pass through that... so whichever nipple looks to pass the gas through the pad should pipe up to the engine vent. The other one... hmmm. might be another water/oil drain that goes behind the engine, should have that mouth bit as well.

[TwoTired]

I've purchased all thses hoses from Honda.  The botton of te box is a water drain with a "pinch tube" end.  The side to the box fitting goes to the top of the hvavl cover via and hose.

The air box plenum is a drain for over filling carbs.  And, oddly, it does not have a pinch tube, but is a reduced diameter hose.  They all route between swing arm and back of engine case.

Cheers,

[FunJimmy]

I thought one of those fittings/hoses was for the fuel tank breather.

[TwoTired]

All the 550s have the fuel tank breather in the gas cap itself.

The F model tanks and the 77-78 K model tanks have an extra hose for the well drain under the gas cap door.  But, that just routes to the bottom of the bike, too.

Cheers.

[scadaman29325]

Thanks! That is what I needed to know.

Now I got to find some hoses...

Thanks again!
Later, Phil