Exhaust on Craftsman

[lawnduster]

My 70's craftsman 8 HP runs very strong and I work it hard. (I made the throttle go a little bit wider open than it is supposed to) But after running it for awhile the muffler stated to turn a glowing red. Is this normal?

 

[Gatorboy]

<font color="blue"> ( Is this normal? ) </font>

Yes

 

[lawnduster]

thank you