redhot exhaust pipe

[yellowjacket]

hey all, just a quick question, I was warming up my bike tonight to come home from work and i peeked under the bike and the first portion of the exhaust pipe (connected to the engine) was red hot, I mean it was amber glowing red hot.  the choke was full throttle and once i tuned it down, the glow went away.  is this normal?

[El Matador]

Yup. Don't worry bout it...

[Holden]

http://www.youtube.com/watch?v=56zbHewJHJE

[Howie]

What you saw was normal, but not a good idea.  High engine speed with the bike stationary means not much air cooling and can cause the engine to overheat.  As the idle speed raises adjust the choke or fast idle lever, whichever you have, to correct idle speed.

[Slide Panda]

Nothing of value to add on the subject - but just the prelude to the above video

http://www.youtube.com/v/lIOZ7tQ98-U&hl=en&fs=1

F1 engines are nuts...

[Heath]

hey all, just a quick question, I was warming up my bike tonight to come home from work and i peeked under the bike and the first portion of the exhaust pipe (connected to the engine) was red hot, I mean it was amber glowing red hot.  the choke was full throttle and once i tuned it down, the glow went away.  is this normal?

In the manual it says to start with the choke open.  This is if you are in cold conditions.  As the bike is warming up back it off to 1400-1500rpm.  As the engine warms up, move the cold start lever gradually towards the closed position.  Once fully warm, the engine should hold idling rpm with the cold start shut down.

I usually run mine about 2k rpm until it warms up a little, then back it off.

[RB]

I would check your exhaust gaskets, at the head, and the primary header pipe. Did both headers glow?

If there is a leak in the gaskets it can actually be letting more heat escape and instead of going out the exhaust pipe , it is venting thru the gasket near the head.  If this is the case, you had beter get it fixed ASAP.
Exhaust gases can average around 600f to 800f.

RB

[Ducnial]

Normal behaviour Yes,  something you should allow to occur No.   Its not the red hot exhaust pipe but you can probably imagine how hot the exhaust valves, guides and surrounding ports get, and the head is only made of aluminum.  Might be running a lean too, that will make it worse.  Looks like your bike might be carbed vs FI  or no O2 sensor.  O2 sensor bikes run notoriously lean so not much you can do about it. 

[yellowjacket]

Normal behaviour Yes,  something you should allow to occur No.   Its not the red hot exhaust pipe but you can probably imagine how hot the exhaust valves, guides and surrounding ports get, and the head is only made of aluminum.  Might be running a lean too, that will make it worse.  Looks like your bike might be carbed vs FI  or no O2 sensor.  O2 sensor bikes run notoriously lean so not much you can do about it. 

what does "lean" mean?

[Holden]

what does "lean" mean?

http://en.wikipedia.org/wiki/Air-fuel_ratio

[DucatiBastard]

those vids are frickin' badass!  i'd love to hear an F1 engine in person

[yellowjacket]

In the manual it says to start with the choke open.  This is if you are in cold conditions.  As the bike is warming up back it off to 1400-1500rpm.  As the engine warms up, move the cold start lever gradually towards the closed position.  Once fully warm, the engine should hold idling rpm with the cold start shut down.

I usually run mine about 2k rpm until it warms up a little, then back it off.

gradually easing up on choke did the trick. no more hot pipe. i was typically starting my engine with fully opened choke and not easing up the lever at all. thanks all for the feedback.

[MotoCreations]

Also cavaet for those who get their exhausts coated (ceramic/jethot/etc) -- get a few heat cycles into them before running your engine ala the above or WOT on the dyno. (dyno's are notorous for overheating headers)  Usually only damage is burned or heavily dulled coatings in first 10inches of header.  Ever exhaust coater has a disclaimer posted at their site in regard to this.

If you polish your headers to a chrome finish -- they will turn a deeper color red for some reason.  Years ago when dyno'ing the IMSA GTP engines, we noticed this affect when testing with different header assemblies.  It didn't take very long at racing speeds though for them to get that dirty black look to them again...