header glowing?

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generallee

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just putting the scamp back together after paint only had it started prob 4 or 5 times since built when i started it i couldnt get it to stay idling i had to keep pumping it and as i was doing it i noticed header tube #5 started glowing red! is this a carberator problem??
 
I had a bad dwell adjustment cause that in the past. But of course it was both manifolds doing it not one hole.
 
Its possible but not entirely likely as you said only one tube is turning red.. Usually see red tubes from unburnt fuel dumping into the tubes where it burns in the tube and turns them red real quick. Could be something bad in the valve trains, bad timing, plugs etc.
 
maybe a mouse found his way in and is wearing a fire retardant suit and blocking that hole?
Sounds like a blockage problem or for some really weird reason- its firing late in that cylinder?? Maybe the header is just "thin" there? Is it right next to another exhaust-like one of the middle set? Maybe you have an exhaust leak there and the other exhaust is "bleeding" into that pipe also- keeping it hotter. Hell- good question! It does sound like a blockage or thin wall problem.
 
A lot of guys here are in the right church but the wrong pews.

It could be timing, but it's odd that it only affect that one cylinder. If it is timing it would be RETARDED not advanced.
It also could be running LEAN which would cause the exhaust temp to rise. Unburned fuel has a tenancy to cool the exhaust gases because they haven't ignited to cause heat.
Also could be an exhaust valve that isn't closing fully or is opening early.
I'd start with a thorough going over it for the basics, timing, check for vacuum leaks etc., make sure the carb is adjusted right. Not just the mixture screws, but the floats as well. If they are low it could go lean. Then check it with a vacuum gauge to verfy the mechanical condition of the engine. Valve timing/ sealing etc. Followed by a cylinder LEAK-DOWN test, not a compression test. Leak-down is more acurate because a compression tester only measures peak pressures, a leak-down is more stable.
Good luck, I hope this will help.
 
Use a thermometer to check the temps of the other pipes. This will help you to narrow it to just the one tube. The other tubes could also be very hot, but just below the temp it would take to get them to glow.
 
Maybe I did not read the entire thread, but I would believe this is combintion of issues. First adjust the valave, sounds like there may be an issue there. Next, the carb and timing, too lean and too far advanced. After that I would worry about the valves sticking etc.. and work back
 
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