What are the symptoms of a stopped up muffler?

[sbklf]

81 Marathon 244 Robin 2 cycle. What exactly happens, is it excessive oil that stops one up?
how do you unstop one? Can I tell if it is stopped up by trying to blow thru it? Can I run with the muffler off to confirm it is the problem?

[Hank Hill]

In regards to cleaning, I believe you can just remove the muffler and place it in a piping hot charcoal BBQ pit over night.

[Hank Hill]

Or, more appropriately, dig a hole and fill it with coals, as to avoid your BBQ pit being seasoned with engine excrement.

[sbklf]

Does that burn the oil out of it? If so, could you just flush it with fuel and and get the same results?

[Hank Hill]

That's just the re-occurring DIY method that I've seen repeated several times here, someone else might be able to chime in on the efficacy of a fuel flush method.

[Revolution]

The fuel flush will not remove burnt on hydro carbons. The high heat of the burning coals will remove all the carbon. It also normalizes the steel as an added benefit, which will reduce the chance of stress cracks in the future.

[sbklf]

If I can blow thru the muffler with seemingly no back pressure at all, would that indicate that it is OK?

Can you be more specific on how to go about burning it clean (how long, do you just lay it in the coals, stand it on end, do you rotate it occasionally...)

Can I expect to use a whole bag of charcoal?

[raydhd]

Originally Posted by Hank Hill

That's just the re-occurring DIY method that I've seen repeated several times here, someone else might be able to chime in on the efficacy of a fuel flush method.

We do use kerosene to soak my brother inlaws D model harley.We let soak and the flush it with more kerosene and let soak we repeat this until we see little color in the soak. We then flush the kerosene with hot soapy water until it is clear.This has worked well and looking in both ends it looks very clean.Haven't tried the bbq method so can't compare which is best.