Make My Pipe Chrome Again, Please!

June 5, 2008 8:24 PM

This evening I bought a vintage 1982 Yamaha XS400RJ SECA motorcycle with under 2600 miles on it. One of the two chrome exhaust pipes is discolored from overheating somewhere along the line. Can I make it silver and shiny again? It's pristine otherwise and runs like a top.

This marked the first time in 32 years I've ridden a bike, and I'm kind of proud of the fact that I managed to test ride it with dropping it, missing a shift, or otherwise making an ass out of myself.

In its past life, one of the cylinders obviously got really hot and the whole pipe is discolored. Since the motorcycle runs so well, and from discussions with the current owner (who rebuilt the engine), I'm inclined to believe that whatever caused this problem has been fixed and is no longer an issue.

There's the normal bluing where the pipe exits the cylinder head, which evolves into a an amberish, burned looking tone pretty much from that point to the end of the muffler.

In other words, I think my only problem is cosmetic.

How can I make this pipe look as good as the other one?

Bonus quetsion: I paid $1750, which is well over blue book, but it has a new battery, new tires, new brake job, and except for the pipe thing is a real cherry.

Did I do OK?

posted by imjustsaying to travel & transportation (3 comments total)

If you're happy, you've done OK. Condition is always worth paying for. Congrats on the bike.

As for blinging your discolored pipe, the news isn't too great (my BSA has a similar issue). There are products like "Blue Job" which claim to remove the blue, and some folks have decent results, but straw and other color blemishes are harder to remove. You also have to keep in mind that the chrome plating is only a few thousands of an inch thick, so any product that does its work by abrasive is removing some of what you're hoping to polish.

If you google "chrome exhaust motorcycle blue" you'll find various bits of "wisdom" about it. Some of it sets off my BS-meter. You're mileage may vary.
posted by maxwelton at 8:46 PM on June 5, 2008

You'll have to re-chrome it, most likely. It's funny, a lot of old-timey hot rodders do things *specifically* to get that look.

Usually, pipes get that hot from the carbs being leaned way the fuck out (or in the case of my Impala, i'm an idiot and set the valve lash two turns too tight, so the exhaust valves let still-burning air-fuel into the pipes, for the whole 20 minute cam break-in period!)
posted by notsnot at 5:40 AM on June 6, 2008

I've had decent results with Simichrome, but notsnot is correct; chrome pipes, unless double-walled (and sometimes even then) will blue with use. Typically the bends in the headers will blue first.

If you have no intention of riding this bike (show bike), get the pipes re-chromed. If you do intend to ride it, take your header off and send it to Jet Hot, who will bake on a finish that will not blue. Jet-Hot isn't a perfect chrome finish, but it's the best you'll do for a bike that gets ridden. Or just learn to live with blue pipes, like most of us do.

About the running lean thing... notsnot is again correct that a lean engine condition can cause pipes to blue, but it is my experience that some motorcycles will blue their pipes no matter what the mixture is. Manufacturers view the chrome as a protective anti-rust coating and not a cosmetic treatment, and do not consider blued pipes a defect. Some manufacturers (notably BMW) have gone to stainless steel header pipes. They blue like a sumbitch but nobody expect stainless steel to be chromey, so few people gripe about it.
posted by workerant at 8:37 AM on June 6, 2008