Motorcycle Repair: front exhaust pipe, 2005 honda crf450x, fuel mixture


Question
Just bought a 2005 honda crf450x,after idling for abought 5 min.the front exhaust pipe is glowing red hot.Never owning a 4 stroke enduro before,the noisy engine is normal to my suprise.Is this normal

Answer
Anthony,

this is not a bike to let idle for more than a minute
or two. They get hot very quickly and often
a red pipe is normal if not moving.

To be safe, you should check the spark plug color
after a fast run and make sure it is not running
too lean a fuel mixture.
http://www.verrill.com/moto/sellingguide/sparkplugs/plugcolorchart.htm
Too lean will be a white or very light colored plug.
A light brown or tan color is ideal.
If the color is okay the mixture is fine.
If not, you may need to go a size larger
on the idle and main jet. Standard is usually around #45idle/#160main

The carb needle can be richened by dropping
the clip on the needle a notch or two.
Also check the carb boots or rubbers for cracks or
leaks. This can lean out the fuel mixture by letting
air in the intake system.