Exhaust pipe temps w Infrared Thermometer

[rug_burn]

With not too many options for adjusting those 6 carbs, I have been checking my exhaust temps with my handy-dandy Harbor Freight  IR thermometer.   I got it a while back,  and they're still about $25 I think.   

They seem to work pretty good, giving at least a relative number so you can compare cylinder temps.  Absolute accuracy I don't know about, but the readings I get seem reasonable.  One thing is that you want to get real close to the pipe, and aim the thing at a part of the header that is not shiny, which mine has plenty being a 97 with the original stock pipes.   The little red beam is actually about an inch above the sensor, so not that useful in this case.
 
Checking the header pipes as they just come out of the head, I get temps in the range of 325 to about 500F  after driving back to the garage around 25 mph, neighborhood speeds, and record the temps 3 times like every 5 or 6 minutes letting it idle. They mostly all settle down to 325-450F after idling a while.  The trend as it cools down is very useful I find.
I also find you gotta be careful not to get it on Celsius or centigrade readings, which is easy to do inadvertantly.

I caught one cylinder that was going cold after riding, which was way too lean and missing.  I it went down to the low 200's, and even below after idling.  It was the #4 cyl;  I enrichened the idle needle about 1 turn, and it's better now, but still tends to go a little on the cold side, in the high 200's after settling down.    I also caught a couple real hot ones which I enrichened, too.  But it's not always clear what's going on.

Any of you Valk riders do this?    What numbers do you get from your bike?   

I was talking to the service manager at our local Honda/Yamaha dealer, Moto United, a longtime mechanic who told me that most owners and DIY types spend way too much time worrying about carb mixtures.         He says the best you can do is get them get them all firing approximately the same, and when you get above about 1/4 throttle they come off this adjustment, and onto the midrange  and if they run good here then don't worry about them anymore.   Funny, eh?  Probably good advice.

Can't seem to post the picture...

[98valk]

too rich or too lean, pipes can be high temp.  pipe temp is mainly a race technique and mainly after the engine is already dialed in. last I read it isn't really used too much.

the way the GL1500 engine is cooled the cylinders will always have different plug readings from each other.  biggest difference is the front two compared to the other four, for two reasons the cooling as I mentioned and that they get their fuel from the middle carbs. Marc the owner of FactoryPro actually saw this when dynoing a valkyrie for their jet kit and why the needles and main jets have different settings for the front two.

do u have air box and/or exhaust mods and trying to dial it in?

[rug_burn]

No, I got no mods, but a couple years back I let it sit too long, the gas went bad, and I had to go thru and clean and put new gaskets and low speed jets in all my carbs.  I synced them all , then I been trying to get the mixtures all right ever since.    They're pretty good right now, but I still notice differences at certain times.    The thing is that I never paid that much attention before this problem, so maybe I'm just noticing differences that were there all along.  It's how it always is

[98valk]

No, I got no mods, but a couple years back I let it sit too long, the gas went bad, and I had to go thru and clean and put new gaskets and low speed jets in all my carbs.  I synced them all , then I been trying to get the mixtures all right ever since.    They're pretty good right now, but I still notice differences at certain times.    The thing is that I never paid that much attention before this problem, so maybe I'm just noticing differences that were there all along.  It's how it always is

what differences at certain times and how? plug reading, etc.?

[MarkT]

I don't have much to add, other than I bought one of those HF thermo guns years ago and it didn't work right then.  And now doesn't work at all with literally no use, and never has.  Typical HF Chinese junk.  I've found anything with "Chicago Electric" name on it would be more accurately named "Piece of Ѕhit".  Buy any battery tool from them and it fails reliably on the first use.  They think giving it an American sounding name buys them credibility via using our good reputation.  They have no shame.  Scammers.  I'd like to see some sort of product protection against their BS.  But then I can't stand our government's overeach into private business so what are ya going to do?  Leave it up to the individual to find out for himself through getting ripped off I suppose.  Or somebody like me who has been ripped off to warn others through online media.

Now on the other hand, I have three 1/4" die grinders from HF, the ones marked "Professional" that have been powerful and reliable for years of daily use - outlasted Craftsman air tools.  Different brand name but still from HF and China.  So it's possible for some of them to make good products.  That goes for Apple products, too.

[rug_burn]

98Valk:
    What differences do I hear?   
    Well, at low rpm, taking off from idle or sometimes decelerating, you can just hear some cylinders are firing a little stronger than others.  And you can actually hear it in the geartrain, it almost sounds like there's a little ruggedness in the whine of the gears;  you guys might think I'm losing it, but that's kinda how it sounds, for lack of a better description.   
    Like I was saying, I wish I'd paid more attention  to how the engine sounded, before I had the problem because once you get tuned into that 6 cyl repeating firing sound, you begin to wonder if it was that way all along, just as irregular or worse, but you just never noticed.     

[rug_burn]

MarkT:
        I see you got one supercharged Valk?   
   What about the carbs?   Are they still there, or does someone make a fuel injection system for 6 cylinder engines in this displacement range?     Wouldn't that be the best solution to all our travails with these carbs?   
     It actually might not be that hard to do.  Actually, now that I think about it, yes, I think that BMW 6 cylinder has fuel injection.     Wouldn't be cheap, though, would it?
     I do a certain amount of electronic design work, and I was thinking that a 6 cylinder EGT (exhaust gas temperature) gauge wouldn't be that hard to do;   one of the major IC chip manufacturers makes a chip specifically for that purpose, with a max of 8 channels (8 cylinders max).   The chip costs about $6, if you can believe that, but a lot more goes into it.     An EGT is what is used in airplanes to set the mixture, and in theory, it oughta work on any gas engine as well.  If I get a great deal of extra time or inspiration, I'll see what I can do ,  but no one should hold his breath on that one.

   But, as far as the Harbor Freight IR thermometer-  yeah, I'm with you, and skeptical about their tool quality, in general.    Mine actually works, wonder of wonders, and for  $25, it's  a good tool to have, limitations noted, especially as to exhaust tube temperatures with slow cooling or heating rates. 

[MarkT]

MarkT:
        I see you got one supercharged Valk?  
   What about the carbs?   Are they still there, or does someone make a fuel injection system for 6 cylinder engines in this displacement range?     Wouldn't that be the best solution to all our travails with these carbs?  
     It actually might not be that hard to do.  Actually, now that I think about it, yes, I think that BMW 6 cylinder has fuel injection.     Wouldn't be cheap, though, would it?
     I do a certain amount of electronic design work, and I was thinking that a 6 cylinder EGT (exhaust gas temperature) gauge wouldn't be that hard to do;   one of the major IC chip manufacturers makes a chip specifically for that purpose, with a max of 8 channels (8 cylinders max).   The chip costs about $6, if you can believe that, but a lot more goes into it.     An EGT is what is used in airplanes to set the mixture, and in theory, it oughta work on any gas engine as well.  If I get a great deal of extra time or inspiration, I'll see what I can do ,  but no one should hold his breath on that one.

   But, as far as the Harbor Freight IR thermometer-  yeah, I'm with you, and skeptical about their tool quality, in general.    Mine actually works, wonder of wonders, and for  $25, it's  a good tool to have, limitations noted, especially as to exhaust tube temperatures with slow cooling or heating rates.  

"George" - the red blown bobber below - has a single carb supplied and tuned by Magnacharger.  Works likes it's supposed to.  However there are injection system(s) available for this bike.  Bob (Attic Rat) has pushed for me to have him install one.  That might happen if I get a round tuit before he retires.  (He's older than me and I'm collecting SS though haven't actually retired yet - just not actively promoting for business; taking it as it comes.)  I'm not unhappy with George's performance; makes around 150hp and the more power I force from him, the more I ask for breaking something.  I recently installed a Dyna3000 and the big VTX coils which fixed a flat place on the power curve, and hard starting.