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Author Topic: blued pipe  (Read 1887 times)

donkey

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blued pipe
« on: November 20, 2007, 02:12:38 PM »
From 230 km since first kick the pipe gets blue on the 'elbow' but too (and this is the rare thing) on the silencer to pipe conection zone, below the foot brake level. The same as this image, but more pronuncied
"Never mind the track. The track is for punks. We are Road People. We are Café Racers." Hunter S. Thompson
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Café Racer CB400SS
Royal Enfield Bullet 500ES
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deejay

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Re: blued pipe
« Reply #1 on: November 20, 2007, 02:37:53 PM »
Thats because there is a cat converter welded into the pipe in that spot on the stock bikes, which creates a hotspot in that area.

Vince

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Re: blued pipe
« Reply #2 on: November 20, 2007, 02:51:42 PM »
A lot of the pipes do this.It is probably okay BUT before going any further you should check the jetting of the carb. On stock bikes I often run 120 or larger main jets. Sometimes I raise the needle and I also fine tune the pilot screw. The other BIG problem that causes this bluing is break-in procedure. Besides keeping the speeds strictly within the levels in the book, you must limit your drive time. Max running time for the first 200-300 mile should be 10-20 minutes. Then cool to touch. Once you correct any problems a product called Blue-away will take out most of the blue. Follow the instructions exactly. Don't use Blue-away on a regular basis. It  can be hard on chrome in the long term.


LotusSevenMan

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Re: blued pipe
« Reply #3 on: November 20, 2007, 03:32:09 PM »
See http://bmwriders.com/technical.htm

It DOES help with chrome pipes too!!!!  ;)
« Last Edit: November 20, 2007, 03:44:02 PM by LotusSevenMan »
If it ain't broke-------------------------- fix it 'till it is!

Royal Enfield Miltary 500cc  (2003)
Honda VTR FireStorm (SuperHawk) 996cc 'V' twin
Kawasaki KR1 250cc twin 'stroker
Ducati 916 'L' twin

Peter

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Re: blued pipe
« Reply #4 on: November 20, 2007, 05:02:01 PM »
Check your timing. You may have too little advance. Retarded timing will fry your exhaust valve.
I don't remember exactly how far the blueing can safely go but I believe it is about 4"along the down pipe  in the Bullet. And yes, the other bue spot is the cat.
Search Bulletech or Nabble Enfield and you will find the answer to this question and more.
Mine is ping timed and is blued only for 1-2".
I don't know if you have a problem or not, but this is something you need to know all about anyways.

Happy riding,

Peter

(And by the way, in the pic you posted it looks just fine)
« Last Edit: November 20, 2007, 05:03:39 PM by Peter »

LotusSevenMan

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Re: blued pipe
« Reply #5 on: November 20, 2007, 05:15:16 PM »
Ignition Adjustment
...also called Spark Timing, Advance Setting, etc.
The idea is to get the spark to ignite the fuel-air mixture
at the right time so that the resultant combustion imparts
the maximum possible energy to the piston at any engine speed.
Adjusting the Spark Timing
The timing of the spark, like that of most things in life,
is of utmost importance.
Recall that the combustion-front formed at the spark-plug
is moving down while the piston is moving up; and ideally,
they meet at TDC and the piston is thrust down to BDC,
by the combustion-front in the Power-Stroke.

* What happens if the spark takes place too early ?

The combustion-front hits the piston yet to pass the TDC.
This "head-on" collision pushes the crankshaft
in a direction opposite to that intended,
which is nothing but the dreaded "back-kick" of the Bullet.
In less extreme cases, the engine will run,
but with a pinging sound from the collisions,
and less power due to losses in the said collisions.
Prolonged running in this condition can damage the piston,
extensively, and so is to be avoided, scruplously.

* What happens if the spark takes place too late ?

If the spark is too late, the combustion-front hits the piston
when well past the TDC, already far and accelerating rapidly away.
The transfer of energy to the piston is less,
and the mixture may be still burning when the exhaust-valve opens
discharging it into the silencer.
Maybe overheating & oxidising the exhaust-bend to blue colour.
Prolonged running in this condition overheats the entire engine,
ultimately leading to seizure in extreme cases.

If it ain't broke-------------------------- fix it 'till it is!

Royal Enfield Miltary 500cc  (2003)
Honda VTR FireStorm (SuperHawk) 996cc 'V' twin
Kawasaki KR1 250cc twin 'stroker
Ducati 916 'L' twin

Roger

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Re: blued pipe
« Reply #6 on: November 21, 2007, 04:45:10 AM »
Interesting... I have covered over 2000 klms (1200 miles) on my 05 Classic and no bluing anywhere. No exhaust leaks at the head or where the muffler joins the header pipe. Mined you, I do mainly suburban riding mixed with a little expressway.

Roger

Thumper

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Re: blued pipe
« Reply #7 on: November 21, 2007, 08:17:13 AM »
Pipe discoloration is due to heat. This might not indicate a problem. As a previous post indicated heat also builds up at the catalytic converter at the end of the exhaust header and before the muffler. Most chromed exahust headers will blue if they don't have adequate heat shielding inside the pipe (e.g., an inner sleeve).

Discoloration usually means:
a)The engine works
b) The pipe has been hot
c) Blue looks cool to real gearheads

Since I began riding motorcycles in 1978, I've had bluing occur on the exhaust headers of my motorcycles:
1971 Honda CB175
1976 Yamaha XS500C
1980 Suzuki GSX450
1981 Yamaha SR500
1980 Honda CB750F
1971 Honda CB175 (another one)
1972 Honda CB175 (another one, this one a cafe racer)
1986 Yamaha SRX6
1994 Harley XL883
1972 Harley Sprint 350SX
1972 Yamaha XS2
1976 Honda Goldwing
2000 Ural Deco
1998 Ural Tourist
2006 RE Electra X

The bikes were in good tune and performed nicely. Discoloration occured on stock exhaust headers on some of these bikes and on aftermarket exhaust headers on other bikes.

With the exception of the 2000 Ural Deco, I never had heat-related issues with these bikes. The Ural was an exception as the 750cc upgrade engine was jetted lean and had the coil located under an engine cover. I corrected both weaknesses.

Like so many other modern motorcycles REs must meet stringent emissions standards - which usually means running lean - which usually means a hotter running engine - which usually means hotter exhaust gas temperatures - which often means discoloration of the header pipe. I have not heard of any reports on this forum where that indicates a problem.

Matt
« Last Edit: November 22, 2007, 10:12:56 AM by Thumper »

Peter

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Re: blued pipe
« Reply #8 on: November 21, 2007, 06:05:02 PM »
.... This in no way indicates a problem. ...

As most blanket statements go, this is bad technical advice.

Everything in moderation, is all I can say about that.

As a Real Gearhead would put it: It depends; on the engine, the state of tune etc.

Find out what's considered ok for the Bullet.
Up to but not all around the first bend as far as I remember, I don't care much about it because I ping time, if you do too and the pipe is blue too far  down you are way lean and you have to fix that.


Peter