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Panhead rear header pipe glowing orange

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JohnnysCustomPaint
Posts: 30
Joined: Mon Dec 13, 2010 5:25 pm
Bikes: 1959 Duo-Glide
1979 Electra-Glide
Location: Florida

Panhead rear header pipe glowing orange

#1

Post by JohnnysCustomPaint » Tue Apr 19, 2011 7:42 pm

I just finished with my 59 Pan and started it last night.
It started quite easy considering all new pistons, rings, bore job, etc.
My intentions were to start it, let it get up to operating temperature, kill it and let it cool completely down.
This is what the old guy that actually sold the bike new told me to do the last rebuild some 25 years a go.

Anyway, I had the BIG shop fan blowing on the bike to simulate going down the highway.
I would gas it slightly every now and then, never revving it much at all, but never letting it lug either.

It started to kinda start missing slightly.
It was just getting dark and I noticed the rear header pipe was glowing orange, mainly at the first bend area, about 1 inch from the clamp and extending down about 5 inches.

The bike has Paughco duals.
Has the finned cast iron -55 clamps.
The plugs are HD 3-4's.
Points are gapped at 22.
It has O-Ring type intake seals, with solid stainless bands for clamps, similar to Sporty exhaust clamps.

What would be your idea of the glowing pipe?
The front discolored almost as bad, but I didn't notice any "glowing, but I am sure it was close to it.
I shut it down as soon as I noticed it and have not done anything as of now.

Thanks for any solution to the problem.

Johnny
johnnyscustompaint@comcast.net



Bosheff
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Location: Michigan

Re: Panhead rear header pipe glowing orange

#2

Post by Bosheff » Tue Apr 19, 2011 7:50 pm

Possibly suckin air, lean carb setting or maybe retarded timing....bosheff

Cotten
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Joined: Mon Aug 26, 2002 9:09 am
Location: Central Illinois

Re: Panhead rear header pipe glowing orange

#3

Post by Cotten » Tue Apr 19, 2011 9:29 pm

Johnny!

Whenever severe heat is generated quickly,
a vacuum leak ('suckin air' as Bosheff put it) is the first thing to suspect.

Not that only one thing ever goes wrong at a time.....

I suggest pulling the carb back off (Linkert, right?) and pressuretesting the manifold with bubbles.
In fact, I suggest pressuretesting while installing any O-ring assembly.

Although this addresses older designs,the principle is the same: http://virtualindian.org/11techleaktest.html

No more than 15 psi is necessary, but the air supply must be constant: not just a tire or air mattress pump.
A #9 rubber stopper with a hole through it works as well as a testplate, but it takes three hands.
The pancover screws over each intake port should be tested as well, and be sure to rinse off the soap thoroughly afterward.

You may wish to them turn the motor through to pressurize each cylinder to test the headgaskets, sparkplug seals, etc. The pressure can be increased greatly for those tests, but a rubber stopper will be hard to hold in the manifold.

If the assembly is totally bubble free, we can then go on to other variables.

....Cotten

duoglide58
Posts: 117
Joined: Mon Apr 09, 2007 7:08 pm
Location: Oklahoma City

Re: Panhead rear header pipe glowing orange

#4

Post by duoglide58 » Wed Apr 20, 2011 2:21 am

I think the two culprits have been listed. Vacuum leak and retarded timing. What kind of timer are you running? Is it a manual advance or an auto-advance? Did you advance the timing? Is the auto advance mechanism not functioning or is it just that the initial timing is off.
Doug

Panshovevo
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Re: Panhead rear header pipe glowing orange

#5

Post by Panshovevo » Wed Apr 20, 2011 3:38 am

Any possibility your rear exhaust valve isn't seating? A compression check (leakdown type would be best) would tell you. Or even just have someone turn the motor while you listen to the end of the pipes, if you have duals. Check the other things mentioned above first, if they check out okay, do the compression test.
If it seems to be leaking, check your valve adjustment next.
Regards,
John

JohnnysCustomPaint
Posts: 30
Joined: Mon Dec 13, 2010 5:25 pm
Bikes: 1959 Duo-Glide
1979 Electra-Glide
Location: Florida

Re: Panhead rear header pipe glowing orange

#6

Post by JohnnysCustomPaint » Fri Apr 22, 2011 7:25 pm

Cotten wrote:Johnny!

Whenever severe heat is generated quickly,
a vacuum leak ('suckin air' as Bosheff put it) is the first thing to suspect.

Not that only one thing ever goes wrong at a time.....

I suggest pulling the carb back off (Linkert, right?) and pressuretesting the manifold with bubbles.
In fact, I suggest pressuretesting while installing any O-ring assembly.

Although this addresses older designs,the principle is the same: http://virtualindian.org/11techleaktest.html

No more than 15 psi is necessary, but the air supply must be constant: not just a tire or air mattress pump.
A #9 rubber stopper with a hole through it works as well as a testplate, but it takes three hands.
The pancover screws over each intake port should be tested as well, and be sure to rinse off the soap thoroughly afterward.

You may wish to them turn the motor through to pressurize each cylinder to test the headgaskets, sparkplug seals, etc. The pressure can be increased greatly for those tests, but a rubber stopper will be hard to hold in the manifold.

If the assembly is totally bubble free, we can then go on to other variables.

....Cotten

To the best I can tell there are no intake leak(s).
This is the "latest" effort.

It is a bone stock 59 set-up with the left grip retard/advance.
It has been upgraded to 12 volts with a Bosch mechanical regulator.
The points are now set at 18, instead of the 22 as they were earlier.
I double checked everything and it seems the front pipe was getting red same as the rear, but I didn't notice it at that time.

Now, today, I made sure the timing mark on the breaker body is lined up with the end edge pf the "timing adjusting stud plate". It was a little off, but it still may be, because the whole assembly has been chromed and there is barely a mark that I "think" is the old mark.

Anyway, the timing mark on the flywheel is at the rear of the timing hole.
The fiber on the points is lined up exactly with the mark on the cam lobe (at full advance on the grip and making sure by twisting the unit CCW).

Then I start it and dammed if the front pipe started getting red hot, but I am certain that when I noticed the rear and posted the first time, the front was also glowing.

I was just wanting to shut it down so I didn't screw something up.

I have a couple of pictures of the positions of the marks if you would like to look.
Basically the flywheel mark is at the rear quarter of the timing hole and the mark on the breaker is lined up perfect with the fiber on the points, all this while at FULL advance on the left grip.

I am beginning to think maybe I am off 1 notch on the timer.

Cotten
Posts: 6911
Joined: Mon Aug 26, 2002 9:09 am
Location: Central Illinois

Re: Panhead rear header pipe glowing orange

#7

Post by Cotten » Fri Apr 22, 2011 8:44 pm

Johnny!

If indeed you were serious in your pressuretesting, then..

Please note that "the timing mark on the breaker body is rarely, if ever, perfectly lined up with the mark on the end edge of the "timing adjusting stud plate".
Otherwise,we would just put it there and forget it.

Timing is not arbitrary, and the Factory's circuit-breaker stakemarks were only used to make certain things were in the right quadrant of the Universe.
Every assembly should be precisely timed by either a static line, or strobed for perfection.

The heat your motor is producing is severe and unusual.
Never does only one thing go wrong at a time.

....Cotten

JohnnysCustomPaint
Posts: 30
Joined: Mon Dec 13, 2010 5:25 pm
Bikes: 1959 Duo-Glide
1979 Electra-Glide
Location: Florida

Re: Panhead rear header pipe glowing orange

#8

Post by JohnnysCustomPaint » Fri Apr 22, 2011 8:54 pm

Cotten wrote:Johnny!

If indeed you were serious in your pressuretesting, then..

Please note that "the timing mark on the breaker body is rarely, if ever, perfectly lined up with the mark on the end edge of the "timing adjusting stud plate".
Otherwise,we would just put it there and forget it.

Timing is not arbitrary, and the Factory's circuit-breaker stakemarks were only used to make certain things were in the right quadrant of the Universe.
Every assembly should be precisely timed by either a static line, or strobed for perfection.

The heat your motor is producing is severe and unusual.
Never does only one thing go wrong at a time.

....Cotten
Do you think I could be off by one tooth on the breaker assy?

jdpan
Posts: 459
Joined: Tue Sep 08, 2009 2:20 am
Bikes: 1952 Custom swingarm panhead
Location: Austin Tx.

Re: Panhead rear header pipe glowing orange

#9

Post by jdpan » Fri Apr 22, 2011 10:28 pm

Heres a picture just for reference.... Yours should be close to this position when fully retarded I would imagine.... The heat youre experiencing is very unusual indeed. How does the machine run?

Image

Hubbard
Posts: 76
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Bikes: 54 FLE, 49FL ,27JD,74FX all customs
Location: Virginia

Re: Panhead rear header pipe glowing orange

#10

Post by Hubbard » Fri Apr 22, 2011 11:39 pm

Any chance you're 180 degrees off? That timin mark will come up on exhaust too. Raise your front intake pushrod tube and turn the motor over, when the pushrod comes down start lookin for your timing mark on the flywheel.

Cotten
Posts: 6911
Joined: Mon Aug 26, 2002 9:09 am
Location: Central Illinois

Re: Panhead rear header pipe glowing orange

#11

Post by Cotten » Fri Apr 22, 2011 11:51 pm

Johnny!

By my experience, it it will be out of the range of time-ability if a tooth off.

...Cotten

Panshovevo
Posts: 293
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Re: Panhead rear header pipe glowing orange

#12

Post by Panshovevo » Sat Apr 23, 2011 2:26 am

What carburetor are you running?

JohnnysCustomPaint
Posts: 30
Joined: Mon Dec 13, 2010 5:25 pm
Bikes: 1959 Duo-Glide
1979 Electra-Glide
Location: Florida

Re: Panhead rear header pipe glowing orange

#13

Post by JohnnysCustomPaint » Sat Apr 23, 2011 2:59 am

Panshovevo wrote:What carburetor are you running?
Stock Linkert MB 74, Hydraulic lifters, pretty much an original scoot, other than 12 volt upgrade.
It has to be something simple that I am overlooking.
I have had this guy for close to 35 years and used to ride the shet out of it.
Then it sat for awhile and got "really refined" , but not rode much.
Then now with a LOT of money & time, I run into this.
It is really like the Twilight-Zone for me.

I have had this bike so long, I feel like I should be able to fold it up and put it in my pocket.

Johnny

JohnnysCustomPaint
Posts: 30
Joined: Mon Dec 13, 2010 5:25 pm
Bikes: 1959 Duo-Glide
1979 Electra-Glide
Location: Florida

Re: Panhead rear header pipe glowing orange

#14

Post by JohnnysCustomPaint » Sat Apr 23, 2011 3:01 am

Hubbard wrote:Any chance you're 180 degrees off? That timin mark will come up on exhaust too. Raise your front intake pushrod tube and turn the motor over, when the pushrod comes down start lookin for your timing mark on the flywheel.
I will do that again tomorrow morning.
It will be the third time, checking this out.

steve_wood
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Location: Belleville, Ontario, Canada

Re: Panhead rear header pipe glowing orange

#15

Post by steve_wood » Sat Apr 23, 2011 3:23 am

Sorry for re-stating the obvious, but how about making the mixture richer? As long as you're sure there are no intake leaks and the timing is right, then that should fix it.

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