OK Has anyone had this happen on a stock bike... seemingly nothing is wrong with it AFAIK. Its all stock.
Cool.
Srinath.
Here's some input (http://www.gstwins.com/forum/viewtopic.php?p=81021#81021) from one of our local experts... :roll:
I'll bring the marshmellows. :mrgreen:
Ok, I know you guys think I'm abby normal but the most common cause of "glowing" headers is 1) Way retarded ignition timing
2) Slightly rich mixture (excess burning in exhaust)
But...I am abby normal, and I love little GS baby bikes and this GS baby forum. :kiss:
C.......
Quote from: KerryHere's some input from one of our local experts... :roll:
Damn... my own words used against me... That not allowed you know...
BUT...
The lean jetting ... or extra lean... or somehitng clogged or blocked up making it lean... I am not seeing any of that. the hoses form air box are intact, the carbs clean and nice ... Yes that was the first thing I checked.. and eliminated. Now just trying to see if anyone has had it happen....
Retarded timing... C... That I dont think is the case... but will check and make sure.
Also C ... A richer mix will not burn in the exhaust... it will end up cooling the exhaust and have a lower temperature. Exhaust Pyrometers measure leanness by temperature... higher the temp, the leaner it is.
Cool.
Srinath.
When I was 13 years old, a friend had a trail90 and we road it all day long. After a while we noticed the header was glowing red. We then checked the oil level to find that there wasn't a drop in it. In that case the problem was low oil. On a side note the next month it was stolen from his back yard, it was sitting right next to a brand new yamaha banshee.
OK ... this has oil... but might not have a working pump... oh wait a sec... that was 2 stroke right... 2 strokes burn much much hotter when they got no oil. This evidently starts to glow in 3-4 mins at idle. BTW I have never seen it myself... just from what he told me.
Cool.
Srinath.
Srinath, understand I am abby normal but just wanted to make sure you understand that a rich condition can cause glowing exhaust. Most people think the only thing to cause hot exhaust will be lean mixtures or retarded timing but a rich mixture can and will a lot of times cause a very hot exhaust condition. It really depends on the homogeneity of the mixture and size of the fuel droplets. If you have a rich mixture with very large fuel droplets suspended in liquid form in the mix then you can very well have excess fuel leaving the exhaust in an unburned form. Once this leaves the combustion chamber and is allowed to expand and vaporize it can mix with oxygen and burn quite hot, causing the pipes to glow. The reason I mention it was because I assumed you had already checked for a very lean condition and would notice the "popping" associated with a lean mix. Although I cannot find any of my papers on the condition I mention, here is a link which I believe helps to explain this phenomenon. www.hv4w.org/info_pdfs/internalcombustion.pdf
One more reason to utilize an O2 sensor in conjunction with EGT when tuning an engine. Love the bike, love the forum.
C.......
I never use an EGT... never have and never will... its reaction is too slow and its much harder to use due to the lack of wiring available to put it where you can see it. O2 sensor only... Have it currently on the eli 1000 and I have used it on the GS to develop the 150 mains and 40 pilots with 3 turns on mix screws and 1-2 #2 washers under needle... OK having said that... this bike currently has none of the above. It has clean carbs that I dare say were set pretty close to stock and they were clean... Now I dont think they'd be too much leaner than factory setting, but too much richer is also impossible. They are stock carbs... Now on a GS... long before you'd get exhaust fire... you'll have spark drown out, and long before you have spark drown... you'll have a fluttery and wayward idle... The bike supposedly glowed red at idle 2-3 mins of starting... liquid gas in the pipe after going through a set of valves... impossible on this one. Timing could be verified, but honestly I dont think any of that is it. If it was leaned out by mixture loos from the valves being tight ... ok maybe... but then again it will run so poorly and not even hold idle.
Cool.
Srinath.
It only takes a couple degrees of timing to affect the EGT's. Have they recently done anything with the cams? Might be a tooth off somewhere.
EGT guage is usually pretty good but the engine has to be at operating temperature. I know on turbo cars, it doesn't take long for it to tell you to back of off on the pedal. Problem with using it on a GS is we never talk about EGT's and the temp range isn't really common knowledge.
Aside from lean carb settings I'm not sure what else will cause a problem you describe.
just a random brainstorm... Can the heat range of a spark plug affect EGT's in this way? what about a bad tank of gas?
I'm not sure if our GS is high performance enough to create high exhaust gas temps from an overly rich condition. Top fuel dragsters are the best example of the fuel still burning as it leaves the combustion chamber. I'm just not sure if the fuel delivery and ignition can handle such a feat on a reportedly stock bike. With a weak ignition, a rich mixture will simply blow out the spark won't it?
:dunno:
Exactly... anyhting off on the GS where mix is concerned...and it simply kills the spark or runs so poorly... you dont get far enough to even see exhaust turning red. My friend was saying I have the mix turned up so rich that the oil is getting washed off the cylinders...and I told him...no way,a mix that's rich enough to wash out the oil will kill the spark long before that... BTW that is the 89 I have trashed for 45Kmiles,not the 11-12K one that turned the exhaust red.
Cool.
Srinath.
I have seen glowing exhaust stacks in other applications (usually super or turbocharged), but not on a bike. I wouldn't think that is a normal state of affairs. My first guess would be a rich mixture too, but then I also bet on Green Bay, so that should speak volumes.
QuoteThe lean jetting ... or extra lean... or somehitng clogged or blocked up making it lean..
this will drive the head and cylender temp high, its cooling down once past the valve, lots really rich mix with some Vacume leaks is what is the main cause of this, seen this in 3 different engines. 1 302 HO ford engine with blown powervalve in holly carb, 2 sbChevy engines with very bad carb gaskets and bad vacume hoses.
the ford's Cat converter was glowing red
the 2 chevys, only time i have ever seen cast Iron exhaust manifolds start to glow bright orange was cutting the bolts with a torch, but these did it idleing.
the fuel that makes it past the exhaust valve continues to burn right on down the pipe. If you pulled the can off the exhaust, you would have flames coming out the end.
Becareful go through the carbs replace the O-rings and gaskets and make sure your jetting is right for your setup, look for vacume leaks and clear them up. being that rich "CAN"( though rare) cause a condition called "Cylender washing" this is the fuel thining out the oil coating on the cyl walls leaving them un lubed.
When I took off the exhaust to paint it I installed it wrong so that it wasn't completely connected properly at the head. When I started it the exhaust leak caused the glowing red you described. I removed the exhaust and reinstalled it correctly, properly seating it into the head and it cured the problem. Freaked me out.
Have you recently removed the exhaust?
OK exhaust leak, intake leak... OK both of which I have to check for and make sure aren't issues... OK I knew that...
Pantablo - This bike has just come to my hands... The previous owner said the pipes glowed red... not a clue what was taken off and when ... Just what I saw from the carbs made me realize... its not the carbs themselves... Though O ring issues could still be at play...
OK I guess I'll see for myself... Yet to get the valve cover off and yet to pull the exhaust. Hopefully its some simple, and not a oil pump not pumping up oil...
Bluknyt - Cylinder wash... On a GS especially a stock jetted one... I really dont think it can ever happen. Even jetted to the gills like the 45K 89 of mine ... You need so much liquid gasoline enter the cylinder its going to be impossible. Maybe somehting with forced carburetion ... like those accelerator pump equipped Smooth bores they slap on the GSXR's of old. I set the floats a mm or so high on the 89, and at idle and under braking the bike will stall... and if you were not hot enough... the plugs will be gas fouled. Basically gas killing the sparkies...
Cool.
Srinath.
start with the simple stuff like the exhaust leak at the head. Then tear into the motor...but you knew that.
Quote from: pantablostart with the simple stuff like the exhaust leak at the head. Then tear into the motor...but you knew that.
Pantablo - Smartass... Just asking cos never had a bike glow before... besides, I have to check valves, I always do. Exhaust leak making it glow also I never heard... but worth checking.
Cool.
Srinath.
Sorry I came across like a smartass. Didn't mean to...
i'd look at the exhaust head pipe bolt area for leak....also a compression test will indicate an open valve quickly
are you hearing any indication of fuel burning in exhaust
my R 1 Ti exhaust glowed once...so did the FJ...it was kewl
Nope never had it running so far... OK been only 3 days so I am a lazy ass clown... OK sue me.
Cool.
Srinath.
QuoteYou need so much liquid gasoline enter the cylinder its going to be impossible
Nope, seen it happen to a buddies honda CBX (inline 6 cyl)
he also confirmed an exhaust leak would help with the Overly heated exhaust, which allowed fresh air into the pipe to burn the fuel that survived cumbustion. Never say its imposible, perhaps improbable backed by unthinkable odds, but never imposible.
By rights, a Bumble bee Can Not fly, they are built incorrectly aerodynamicly, but someone forgot to tell them that.
Quote from: seshadri_srinath I am a lazy ass clown... Srinath.
John, a little help here...... :mrgreen:
Quote from: BlueknytQuoteYou need so much liquid gasoline enter the cylinder its going to be impossible
Nope, seen it happen to a buddies honda CBX (inline 6 cyl)
he also confirmed an exhaust leak would help with the Overly heated exhaust, which allowed fresh air into the pipe to burn the fuel that survived cumbustion. Never say its imposible, perhaps improbable backed by unthinkable odds, but never imposible.
By rights, a Bumble bee Can Not fly, they are built incorrectly aerodynamicly, but someone forgot to tell them that.
The carbs, jets, and everything else on the intake side were stock... and yes air entering at a exhaust leak will make the unburnt gas burn up... but think about it, it will misfire in the pipe when it does... OK OK OK Most likely... and you will say it misfired... before saying glowing red. The bike can be a hair lean... as it was from the factory, and could be having a exhaust leak... so glowing red... I'll start with those as my basis... I doubt its anything more complicated.
Cool.
Srinath.