Valve cover

I'm new to these bikes. Can I just use an earlier model valve cover on my 79 KZ1000 to get rid of the smog system? Or do I have to keep the reed valve with my smog head?

You can use an earlier valve cover, but you have to plug the air passages in the head that go to the smog system. It's been a long time since I had a valve cover off a 1979 KZ1000, but I believe there's just the 2 passages at the front of the head. If you dont plug them, it makes a huge exhaust leak, sounds like crap ect.

The passageways Ron spoke of are journals that lead directly to the combustion chamber and come out in the exhaust valve area. If left unplugged, there is a good chance that flames will come out the holes and that seems like a poor idea since they are right under your gas tank. I suggest you check out APE's products as they sell really pretty billet plates that cover the reed valves and don't have the nasty looking nozzles sticking out of them. I am not positive but I also think the early valve cover won't have room for the cam chain idler... in other words, the older valve cover won't sit down on top that idler and you will have to change that part as well.

Thanks, the APE blockoff plates look like the way to go.

Whatever happened to American ingenuity?
I guess I'm too Scottish (the cheap people, not the booze!) I've got some 1/4" aluminum around here somewhere. I can make my own "billet" cam cover caps, and for a whole lot less than $50! Maybe even personalize it with my initials, or sumpin'. But you're wrong, wg, about where that port goes. It leads from the exhaust port to the pocket under the cap. It is clearly outside the combustion chamber. Between the cap and the pocket are reed valves that (for the most part) only allow gas movement toward the exhaust ports, not toward the rubber hoses and air valve up under the backbone tubes. Now, those reed valves aren't exactly air-tight, so I suppose that there would be a certain amount of blow-by, but there's enough baffling that I wouldn't expect active flames shooting out of there. 'Course, I don't think I'll try it, but I think that just plugging those hose ports with JB Weld would be sufficient, as long as you left the reed valves under the caps. Just

Yeah, just leave the reed valves in and plug the openings with high-temp silicone sealer or JB Weld. If you junk the whole system, be sure to plug the vacuum ports on the carb holders (7/32 vacuum caps work for this) and the air fitting on the air cleaner box (if you still have it) because this fitting is on the "clean" side of the filter - if you leave it open, dirty air can be drawn into the engine.

Post edited by: vegasjetskier, at: 2006/09/09 20:36

Post edited by: vegasjetskier, at: 2006/09/09 20:36

Find yourself a Canadian casting rocker cover.The reed valve EPA pollution control was never included on Canadian models.

I usually make the block-off plates like Pstrbrc says, but others sometimes plug the four little ports coming out of the head with screw-in plugs in order to use older valve covers.

As was mentioned, make sure to block off all of the other openings when you ditch the plumbing mechanism. Don't throw it away, though, motorcycle emission testing will probably come some day in your area.

The Canadian valve covers have little tabs on the valve cover that block of the ports in the head. So the Canadian heads are the same as the US, but the covers are much prettier.

Loudhvx,couldn't have said it better myself.Those reed valve blocks are ugly imho.I've sold spare Canuckistan model MKll & J/GPZ covers to US folks who wanted to get rid of them on their bikes.

The cam chain guide WG refers to are in the J/GPZ models,the MKll has the same cam chain top idler on north or south of the border models.

Post edited by: Jack, at: 2006/09/12 15:34

Jack ,and I got one of your MKII covers and it looks great.Thanks mark

yeah,now if somebody had one for a gpz head laying around cheap!:whistle: