How hot should muffler get?

[SmilingBob 11]

Have a 1979 Wheel Horse C141 The engine is a Kohler K321AS-60322D engine with a Nelson muffler . Ran it for a few minutes at full throttle and checked  the temp of the muffler with a non-contact Infared thermometer and it was showing 500 degrees is this normal?

 

SmilingBob

[CCW 1,333]

Not sure but try it on your car and lawn mower and see if there is any comparison.

 

[Gasaholic 257]

pretty normal, I'd expect to see around 400 to 600 degrees depending on a number of factors including ambient temperature (intake temperatures can reach 250 degrees) and amount of load on the engine. Direct exhaust gas temperatures can get into the 4 figures easily enough. 

[ri702bill 8,967]

Agreed. IF the muffler is glowing orange or red there IS a mixture problem - engine like that is running WAY too lean.....

[RED-Z06 2,479]

Mufflers get hot...exhaust gas temps can hit 500* on smaller kart engines, i see head temps nearing 300* mowing in the summer, i know my muffler is over 800⁰.  My kohler twins all have visible muffler glow at night while mowing, that takes around 900⁰, my onans will cherry up right at the muffler can walls opposite the inlets.  I dont worry too much about it.  If the plugs come out good and the engine runs healthy, the rest isnt really an issue.

 

In 2020 I mowed really late in the evening with my C100/K241 and when i got off in the dark in my shop the muffler can was mostly glowing.  This is with correct points, correct carb, good fuel, plug comes out a light cocoa brown.  Muffler is painted with White 1100⁰ muffler paint and it held up 18 months and never flaked.

[Rick3478 434]

We used to say "dull red at night is just about right".

[RED-Z06 2,479]

On 8/15/2023 at 10:02 PM, Rick3478 said:

We used to say "dull red at night is just about right".

Yep