The Zephyr Zone

My ZR550 is a US-spec model and I want to remove the extra US emissions equipment. I have heard that there is no real major reason to do this other than making it easier to work on the bike (less stuff to remove when you have to access the top end), and one guy on another forum that said it made his bike run smoother. Those are good enough reasons for me.

I understand that the process is pretty simple. Take the stuff off, block the holes, done. What I’ve decided to do is take it one step further and get a Euro/Asia-spec cam cover and replace my stock cam cover with it. So below is a photo of my new cam cover, fresh from being vapor honed.

So my question is really simple. Other than getting a new OEM gasket and installing that with the cover, is there anything else I should consider? I’m hoping this job is fairly straight forward, and that I don’t need to do anything else.

Thanks for your help, all.

Well sir, I did it! New cam cover and gasket installed. Not a difficult job all things considered, and it cleaned up the look of the bike a little. Photos below.

Now I’ve only taken it for a really quick test ride just to make sure it still worked right. I happened to be wearing a new pair of gloves for the first time on this test ride as well. So unless these are magical gloves that made me faster, than there is a serious difference in throttle response after the cam cover swap. She felt like a bat out of hell. It’s gonna take me some getting used to, because hot damn it felt like a serious bump in performance. Further riding will tell if this is real or I’m just crazy.

Technically, the system simply takes fresh air from BEFORE the engine and puts it into the exhaust right AFTER the engine, effectively bypassing it. So is basically an "exhaust treating" system. Other than reducing clutter, it does not affect performance in anyways, neither positively nor negatively.....the 'performance' you feel is because motorcycle is 'lighter' now.

............by the way, modern motorcycles with computers, sensors galore, fuel injection, O2 sensors, and other gadgetry, are still using the system as it is effective burning remaining hydrocarbons in the exhaust.

..............and it will probably remain in use, until all internal combustion engines are banned, and full switch to electric happens...in the next 10 years,....if our planet lasts that long, which I seriously doubt.

.....and yes, I removed the system from mine long time ago to make maintenance easy.........me, bad....like all humans.

The more I think about it, the more I think it must have been the gloves. And yes, that sounds just as silly to me as I’m sure it does to you guys. But some sort of sensory/tactile difference in the gloves was probably just making me ham the throttle more than usual.

To comment on your post HugoJose, I do feel a little bad taking a part out of the bike that helps lessen the emissions. None of the environmental issues of riding a combustion engine motorcycle are ideal. I for one am excited about EV technology and I do hope to have an electric motorcycle someday.

Looking good though