I have a 1990 ZR550 Zephyr project bike that I’m working on. It came to me with the cam cover loose, just sitting on top of the engine with no gasket. I got a gasket, and I could just use the cover I have. But I want to do what I did on my other bike which is to replace the cover with a Euro-spec cover because it eliminates the porting for the PAIR valve emissions equipment, for a cleaner look.
This time I wanted to use a GPZ550 cover because it has the “DOHC” on it and I think generally looks cooler. I already got one, but just realized that the swap is not entirely straight forward. Aside from any other issues, which I am curious if anyone knows of any additional pitfalls in this plan, I realized that the cam plugs are different. Here’s some photos to show it.
The first photo is the GPZ550 with the “DOHC” cover and the second photo is my actual ZR550 with its Euro-spec cover. You’ll notice that the cam plugs are different, the GPZ has a half-circle that looks like it might just be rubber, and the ZR has a full circle that is alloy.
So what does anyone know about this? First of all is there some performance reason for it? The ZR is a newer version of the engine used in the GPZ, so is it some kind of improvement to sealing it up, or just aesthetic? Could I just get some GPZ half-circle plugs and be done? Any other potential issues I’m dealing with here?
Worst case scenario I sell the GPZ cover and just get a proper ZR, but I’d love to make this work if possible.