what causes head pipe to glow

just wondering

Heat does.


The proceeding nonsense brought to you by MotoGreg

On two wheels (or 3) since 1970

'92 GSXR 7/11 (Until I get a shwangy 916)

'99 WR/YZ400F 'Cause thumpers rule and two strokes drool!

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A smart answer for a dumbass question :)

if the exhaust valve opens too early the exhaust flame will escape whilst still burning & expanding.

the idea is that the mixture burns in a controlled explosion & pushes the piston down. when the useful effort of this push on the piston has gone it's time to open the exhaust valves & let it exhale.

if it's done too soon the burning gases go out the exhaust port. the valves are actually quite good at coping with this on modern machinery.

there is also the possibility of running lean. if i remember rightly the temp of a good mixture is 800c & lean can be 1200c!!!

if the bike runs fine it won't be this.

dodgy ignition/ignition timing can burn the fuel too late making the unburnt mixture burn after it got kicked out the cylinder is another.

lets note forget that the header is a single wall thickness pipe. on roadbikes it would be dual & the orange glow wouldn't show & wreck your lovely crome headers.

bit technical i know but i hope i have helped you.


It's normal don't worry about it .It's also normal for your bike to overheat if you idle to long(like 5 minutes)

Same thing happened to my mates bike. It also would not idle properly.He put in bigger pilot jet and that cured it.The bike runs on pilot system only at tick over so if you get some **** int there it can run very lean but be ok when the throttle is opened.A poorly adjusted pilot screw could also have a similar effect.

bend it you mend it racing corp.

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