Importance of exaust header temps?

[Guest]

I have a 81 GS1100E and was wondering if, using a temp gun, the temperature of each header pipe, let's say at the first bend, should be roughly the same temperature for all?
I Know that air cooled the 2 middle cylinders get hotter then the ends. I have 4 pods and a 4to1 what should I watch out for.

[posplayr]

You can play around and if you have gross differences then there is something to fix. However my recollection is when trying to compare shiny chrome pipes for jettinging differences it was difficult to get any real indication.

The Carbtune is probably better for that and even it is pretty worthless except for VM's. AFR is what you need if looking for tuning info or stick with plug chops.

[eil]

Reflective surfaces don't work with an infrared heat gun, but if they headers are fairly non-reflective (rusty or painted), then you can get a decent reading.

Taking the header temps as a quick diagnostic is fine but has its limitations. For example, on my 850, I used to take temp readings of the headers after the bike was started but before a ride. I found that the #1 cylinder was always at least 100F cooler than the other after a couple minutes of idling, which confirmed my suspicions that it wasn't firing at at at idle speeds. (At least, not when the engine was still cold.) After I balanced the carbs and tweaked the idle mixture screws, all of the headers are now a lot closer in temps and it sounds much better too.

[Wingsconsin]

I have a temp gun and use it on my motorcycles for a variety of things.
I measure tire temps to see if one is unusually hot (indicates low pressure).
I measure rotor temps to see if one is unusually hot (brake drag)
I measure header pipe temps as well -- and I have found that my #2 is typically 30-40 degrees cooler than #1,#3,&#4.
I think it may be running too rich - and plan on tweaking the carbs again when I do the valves next, I will re-balance and tweak mixtures just a little.
But the bike runs great, starts right up, delivers decent fuel economy at a consistent 42 MPG (which I think could be better after the tweaking).

The experiment is on-going

[eil]

Hmm, never thought to measure tire and rotor temps, I'll have to try that.

[qcktvr]

Hi,
Yes, they can be useful tools for sure, think 30 - 40 deg F is pretty insignificant though, but cyl #2 is where the vacuum for the petcock comes from and any hole in that diaphragm makes it go rich ( made mine run crappy though until the tip was given to me)
regards

[posplayr]

For what it is worth, I started this thread a few years back to discuss the merits of exhaust gas (CHT and EGT) temperature monitoring.

http://www.thegsresources.com/_forum/showthread.php?161402-CHT-and-EGT-Monitoring-for-CV-CARB-Tuning

While a Harbor freight IR temp sensor is actually a pretty nifty tool (and pretty accurate), I think you would be hard pressed to do any real tuning with one other than at idle.

http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-69465-8905.html