Glowing header pipe

[Fletch1312]

Yesterday I was riding my 2014 Kx250f and while I was riding in 3rd and 4th gear holding half throttle there was a lot of crackles and back fires so I put the bike away and noticed that my header pipe was glowing red so I turned my bike off and then a bunch of coolant leaked out. Any possible reasons this could of happend and how I can fix the back fire. Thanks

 

[RM_guy]

I'm no 4 stroke guy but I'll give it a shot.

Was the coolant leaking out of the overflow? If so it was probably running hot, maybe lean. I've seen header pipes on 4 strokes glow red before so that's somewhat normal but with the backfiring and coolant overflow it would deserve some more investigation.

 

[Kaboom Racing]

Running lean...maybe there is air leaking into the system?

 

[Okiewan]

It's pretty common for a header pipe to glow. Unless you are riding at night (or close to it) you probably just never noticed it.