Skip to main content

Repair guides and support for weed whackers, also known as string trimmers, weed eaters, edge trimmers or line trimmers.

38 Questions View all

Why is my muffler glowing red hot starts right up and seems to run

Meffler gets red hot and glow when full throttle starts fine does not boggle but does seem week

Answer this question I have this problem too

Is this a good question?

Score 2
Add a comment

5 Answers

Most Helpful Answer

The reason the muffler is glowing red is because the exhaust temperature is off the chart.

This (highly likely) means that the ignition timing is out, or the fuel mixture is too lean. One possibility on small engines that run a flywheel magneto is that the keyway/key may have damaged itself or sheared off, allowing the timing to go out. Or, the carburetor is gummed up, not allowing full flow of fuel.

What does this mean? Well aside from the engine going outside of it's safe operating temperature (wearing out components faster), it can also lead to detonation, which is where the fuel is igniting before the end of the compression stroke. This can result in breaking the connecting rod and destroying the engine.

I would not use it without making adjustments.



Was this answer helpful?

Score 2
Add a comment

I have just experienced this problem and the results were devastating. The muffler is bad replace it right away or you will be dealing what I am dealing with. The red hot muffler caused the engine to over heat, it blew the oil right out causing a whole engine rebuild! And getting parts for this thing is ridiculously expensive and that's if you can find them. The muffler is expensive I paid $640 for mine. Before you can get it replaced your engine will burn oil bad. Keep a close eye on the oil or you will be in the same boat as me.

Was this answer helpful?

Score 1
Add a comment

Sounds like its running lean at the high end. Double check the fuel/oil mixture is correct. Also the high rpm has a mixture adjustment on the carb. Best to have someone that has adjusted those before to get it set correctly.

Was this answer helpful?

Score 0
Add a comment

It can be caused by a clogged catalytic converter. It can also be caused by timing being off

Was this answer helpful?

Score 0
Add a comment

I have a 85 chevy astro van 2.5 that will start and idle fine but the exhaust manafold glows red in minutes there is not cats on it and the exhaust is not blocked the dash light showed code 42 so I replaced the icm but that didn't work it back fires and u can only get in 2nd gear 20mph to the floor I'm at a loss iv tried plugs wires coils icm grounds and vacuum lines iv pulled the exhaust off and let's put it this way I could use the flame that's comes out as a cutting torch

Was this answer helpful?

Score 0
Add a comment

Add your answer

Timothy Cavazos will be eternally grateful.
View Statistics:

Past 24 Hours: 46

Past 7 Days: 462

Past 30 Days: 1,869

All Time: 27,133