blue pipes

[Robert Haller]

Hmmmm.... It just seemed really odd that mine went so long unchanged and then discolored after just a ride or two when the only thing different (that I'm aware of anyway) was the outside temp.

[Dennyz]

Hmmmm.... It just seemed really odd that mine went so long unchanged and then discolored after just a ride or two when the only thing different (that I'm aware of anyway) was the outside temp.

That is the same thing my Jardine 4:2's did. I rode the bike all winter and half way through summer. The pipe had a slight gold tint at the first bend. One day I went for a ride and half way through I noticed the pipes had turned blue. T cleaned the pipes back to a gold tint and they stayed that way for a while, but eventually turned blue again. I left them that way.

I have since learned that having the inside porcelain coated when the headers are new will prevent bluing. I have also heard of products that can be done by a DIY'er. The inside is coated and baked in an oven. Dyno Kote (CCI#11-499), or Blue Shield (DS#KR005- from the folks who make Kreem). I would like to clean my pipes up and try these products (some day).

[robywan_kenobi]

Well, I pulled the spark plugs last night and they definetly look white. So I'm guessing the carbs are running lean. Yes, I do have a stock air box. I have another condition that leads me to believe the carbs are running lean as well; when I close the accellerator to coast down to a stop, I'm getting some backfiring. From what I've read here and elsewhere, that indicates a lean condition.

[Dennyz]

robywan_kenobi,

Before you jump into jetting, make sure you don't have any vacumm leaks. I found it common for the carburator boots (engine side) to loosen up at the engine. Try the WD40 trick. Spray around the boots when the engine is running. If it speeds up, you have a vaumm leak.

[thumperjsa]

Definetly lean. As Denny says, make sure you have no leaks past the carbs.

One of my intakes were leaking so bad that the engine was not firing. Made a real funny tinging sound when I sprayed starting fluid at the intakes as the cylinder started to get something to ignite.

If you have no stock changes, then you should not require re-jetting. That is unless a PO did something strange. But that NEVER happens.

[robywan_kenobi]

Is there anyway to richen up the mixture without resorting to rejetting?

[Ken Talbot]

If your '81H is like mine, it will have adjustable needles in the carbs. These allow you to lean out or richen things without replacing jets. Similarly, adjusting the float levels will alter the mixture without touching the jets. Tsunami used to run extremely rich compared to SWMBO's Purple Reign. I moved the needle down one notch and lowered the floats 2mm, and the rich condition went away. My mileage also increased by 10 mpg (imperial gallon).

[Dennyz]

Check your float bowls (which should be your starting place anyway). If they are set lean, you found your problem, if not, fatten them up a bit. It does not take much.

[excess11]

Blue pipes

The statement that my pipes did not turn blue until I rode in 30 degree weather sounds to be a true fact. The colder weather causes dense air and dense air has more available oxygen.So more oxygen and the same amount of fuel will create a leaner fuel mix.You would not think that temps would effect fuel mix as much as they do but altitude also plays a big role.The higher the elevation the less available oxygen. I only know this because snowmobiles are greatly effected by elevation and temperature changes.

[skids]

Re: Blue pipes

Lean running at cold temperatures might have something to do with fuel not being atomized as well do to cooler heads.

Originally posted by excess11
The statement that my pipes did not turn blue until I rode in 30 degree weather sounds to be a true fact. The colder weather causes dense air and dense air has more available oxygen.

[skids]

Re: Re: Blue pipes

Urgh! That sould have read:
Lean running at cold temperatures might also have something to do with fuel not being atomized as well, due to cooler heads.

Originally posted by skids
Lean running at cold temperatures might have something to do with fuel not being atomized as well do to cooler heads.

[Pat Kelly]

Cooler head prevail

[Robert Haller]

We all know that blue headers indicate a lean condition, and I've heard that gold indicates a rich condition. Mine started out slightly gold, but now are magenta (pinkish purple), what the heck does that indicate?

[fredintoon]

Magenta?

Hi Robert,
it means you have an artist's eye for colour.
Magenta is also the official colour for the radiation warning symbol but mostly it defaults to black on yellow as magenta paint is hard to mix right.
Now if your Jardines turn magenta it means they got hotter than the temperature that turns 'em blue. If the magenta fades to blue around the first blend and then to yellow part way down the first leg the exhaust temperature is as it should be. If it magentas & blues clear back to the mufflers you are in trouble & most likely will soon need a valve job.
Note that the colour don't go away even when you adjust the carbs. If you insist on using exhaust pipe colour as a tuning aide you must polish the pipes back to clean chrome after each adjustment.
Fred Hill, S'toon.

[Robert Haller]

thanks for the info Fred. It's only magenta at the header bend. It probably is due to when the baffle cap came off my exhaust and had to ride back on the interstate with no restriction (I had my valves adjusted last fall).