I don't think they did. It's all over some rebel forums that if the pipes are blue, either expect issues or walk away.
I've yet to see one without some amount of bluing. The bikes ran rather lean from the factory back then even when adjusted "perfectly." At least, the CB (Nighthawk) models of the 450 did. The CB models had carbs with slow, main, and secondary jets, and the main jets seemed to be a little undersized.
Looking at the Rebel's carb diagrams though, it appears that it used only two jets, a slow jet and a combined main/secondary jet along with slightly lower compression. They may not have had the same "intentionally lean" issues that the Nighthawk models did.
ZV
I don't think they did. It's all over some rebel forums that if the pipes are blue, either expect issues or walk away.
That just seems wrong to me. I've never had any air-cooled bike that didn't show at least a little bluing/golding on the exhaust right where it exits the head. I mean, the pipes shouldn't be bright blue for several inches, but a light gold/blue hue within an inch or so of the port isn't anything that would worry me on an air-cooled engine.
ZV
I'm not saying that there isn't ANY bluing, I'm just saying that if it's readily noticeable or excessive that it's typically a tell that something isn't right. The rebel typically doesn't show it, at least from the 10 foot glance, it usually isn't even noticeable on all the bikes I've seen.
Needs a front fender.