Exhaust pipe temperature?

One of the symptoms my 82 KZ750 4 cylinder bike is experiencing is that the #1 and 2 exhaust headers are not NEARLY as hot as the #3 and 4 headers when the bike is fully warm.

What should the temperature be when all 4 cylinders and carbs and everything are properly adjusted and the bike is running right? I have a laser thermometer I can point at the headers to determine their temps.

If I knew what temp the headers should be, I could figure out whether 3&4 are TOO HOT or 1&2 are TOO COLD. That way I reckon I could narrow down which carbs/plugs/wires and so on that I need to adjust.

I dont know of an exact temperature but each pipe should be hot enough so that when you spray water on em it sizzles right off. If it dont sizzle then it's not firing, At the other end of the spectrum you dont want a red hot pipe either.

It might be a good idea to take a look at the spark plugs and see what colour they are. This link might help with plug colour

ngksparkplugs.com

Post edited by: steell, at: 2007/02/25 16:01

I noticed this as well on both of my bikes, but I can't figure what would cause this. If anyone has a potential explanation...I'm willing to listen.

Thanks in advance!

Both of my bikes run great; sparkplugs are the right color and carbs are in sync. No redhot pipes or discolored (blue) pipes here.

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Hey HGD,

Given that the ignition is a dual system that runs 1 & 4 on one coil and 2 & 3 on the second coil. And Given that the #1 and 2 exhaust headers are not NEARLY as hot as the #3 and 4 headers when the bike is fully warm.

I'd bet You've got a carb problem.

Might be:
intake leaks
plugged jets
Different float heights

Where's WG when you need him?


KZCSI

Thank you all once again for your advice and for taking the time to help a brother out.

Well, I have made an important, life-altering decision today. I had pulled the carbs out, and removed the tank and air pods, and some other things, when it suddenly occurred to me...

I have two bikes and two cars, and they all run great. So what's stopping me from going postal and starting a down-to-the frame restoration on my KZ beater?? So now it's in even more pieces, and the paint has come off the tank.

I am going to learn as I go, because I know nothing about motorcycles. I know nothing about working on cars, even. But I am going to learn a lot!

I'm going to repaint, replace, fabricate, rebuild, tune up and customize until my head spins. Wish me luck!! And be ready because I'm going to be asking advice every five minutes for the next six months...that is, provided my ass don't get sent to Afghanistan.

You didnt'tell how it rides and if it has power...Besides checking carbs I would check valve clearance!

Well, it handles great but it is incredibly SLOW. It accelerates like my grandmother and it topped out at 67 MPH on the freeway. It only gets about 28 MPG. Or, I should say, it WAS incredibly slow. It doesn't move at all now...it's in pieces!!

Oh, and when I say slow, I mean it was so slow that my 4 cylinder Toyota economy car would absolutely SMOKE it off the line.

270~390F 2-3 inches from head approx you know give or take a bit--has to be over 212 and somewhat equal or you have some carb tuning to do

plug wire end cap resistance
float levels
mixture settings
fuel supply/ delivery

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I don't know the temps, but for sure an infrared thermometer will not work on chrome, so if your pipes are chrome don't bother and also if you have an infrared thermometer it has to be a good one with at least a 16/1 ratio to measure a small area accurately. You can measure chrome if you cover it up with masking tape and measure the temp on the tape, but then you need a high temp rated masking tape or it will make a gooey mess in less than 5 seconds. Just a little info.