TOPIC:

When I purchased my '81 550 GPz, the air box was gone and the emission system hoses were just left loose. I made a good case vent. What should I do with the rest of the system? What about the two valves (vents) that come off the heads?

I think you need that for your 27mm Teikei constant vacuum carbs.

The two "valves/vents" on top of the valve covers are outlets for the exhaust reed valves, and are used to flow any unburnt exhaust gases/fumes back through the airbox and into the carbs to be reburned.
You can either run a hose connecting the two together, or just cap them off altogether, it won't hurt anything - most of us who own KZ's that came equipped with the EPA garbage have done this without any ill affects.

As far as the other (smaller) hoses, I'm not exactely sure on your bike.
Hopefully loudhvx will pop in this thread and be able to tell you exactely what to do with them. He owns several early GPz550's, and I'm pretty sure he's tackled this on at least one of his bikes.

Here's a thread on the subject:
kzrider.com/forum/viewthread.php?tid=25074

The air-suction-system sucked clean air into the exhaust ports from the airbox. The air goes into the ports on top of the valvecover and enters the exhaust through little tubes cast into the head. It is not related to the crankcase ventilation except for the fact that it connects to the airbox. You can eliminate the entire system, but you must cap-off those ports. The link shows some methods including the easiest, which is R4's suggestion of a hose from one to the other.

The vacuum ports on the intake manifolds should be capped as well. I usually use a piece of short fuel line with a metal plug in it, because the rubber caps at parts stores seem to disintegrate in no time.

For the crankcase vent, I just thread a brass elbow into the round cover on top of the trans, then run a clear vinyl hose down to the ground from the fitting.

The 81 gpz550 uses TK22 mechanical-slide carbs, Goose... damn jealous, we could use some sun up here. You don't have to hog it all!

On my bike KZ550, the air system is also removed. I had been planning on getting some small little air filters, like these , to place on those holes on top of the head. Would that be bad? Will it effect engine performance (smoothness - I don't really care about HP)? Should I plug them off?

As for the Carbs, I've already got them plugged off

Are you talking about putting crankcase filters on the reed valve ports on top your valve cover? As loudhvx, the reed valves connect to tubes going to the exhaust runners just outside the combustion chamber. He also mentioned that the two openings on the valve cover should be connected with a hose OR plugged/capped. I use BLACK PERMATEX RTV for this purpose. Having those things open (essentially what you would be doing with those little filters stuck on them) would likely be dangerous since there is a gas tank right above them. The little filter you show is often used on top the crankcase vent located to the rear of your cylinder block on the engine cases.

on my kz750e i managed to get nos english cam cover
we dont have the same emission laws as you guys
this has no extra pipe work on top
bike ran smoother and crisper

KB02 wrote:

On my bike KZ550, the air system is also removed. I had been planning on getting some small little air filters, like these , to place on those holes on top of the head. Would that be bad? Will it effect engine performance (smoothness - I don't really care about HP)? Should I plug them off?

As for the Carbs, I've already got them plugged off

Block them. Sucking clean air in there will cause huge backfires on throttle down. The point of the vacuum-valve assembly was to cut off the air supply at throttle down.