Muffler BBQ

[Dabble Inn]

My 85 has been getting louder lately so I got under it to get a look-see, it was missing one 'exhaust pipe to cylinder' stud and the other one was loose. Guess I shouldn't have used anti-seize on them when rebuilt two years ago, but while fixing that I noticed a lot of gunk had developed on the cylinder around the exhaust port. Considering how much there was in such a relatively short period of time I could't imagine how much was in the muffler after 34 years........

So, since I've never done it before I decided to have a muffler bbq and make a party out of it too. I split the wood rather small to achieve a hotter fire (3 beers). Then got the fire roaring hot (3 more beers), then laid the muffler on it and kept feeding more wood under and above (lost count of how many more beers). I periodically checked the temp of the muffler with a heat gun, The max reading on the gun is 1000* and it kept reading over temp lol......

Not sure what to do with it before installing, would it be ok to flush it out with the garden hose/pressure washer? Maybe bang on the sides of it with a hammer too? Or just install since it got that hot for many hours it must have burned it out?

[CP241]

I gotta admit it's kinda fun when they get the flame thrower happening

I just blew a couple puffs of compressed air through it, bolted it on and ran it. Any soot left over will blow out naturally, don't need to do anything special to flush it.

let us know what kind of a difference it makes in performance. I recently cooked the muffler on my kids little suzuki LT80 and that little thing was night and day difference.

[Dabble Inn]

Well, I didn't see your post in time so I did flush it with the hose. Got a lot of colored water out but that's about it, no chunks or anything. So now I have it on the side burner of the grill to make sure I boil out any leftover water, I'm getting some steam (reminds me of a cute little teapot lol).......

One thing about this muffler is it sounds like a can of marbles when I flip it over, I'm sure the baffles are rusted away inside. I noticed it when I rebuilt the engine 2 years ago but couldn't find a replacement at the time so had to reuse, not sure if that's a bad thing for the back pressure or perhaps the shape of the muffler itself creates the back pressure. The buggy does run great with it.

[gunwhatgun]

O.K. I'm going to expose my ignorance here. How much should one of the mufflers weigh? I ask because when I took mine off to pull the engine, it weighed a ton. I bet it was a solid 20/25lbs. My son even commented on how heavy it was. We talked about burning it out but I wasn't sure people did this on these. We have done them on old 2 stroke bikes before but never for a four stroke application.

[Dabble Inn]

Yeah mine was surprisingly heavy too, and this is a 2 cycle

[CP241]

Originally Posted by gunwhatgun

O.K. I'm going to expose my ignorance here. How much should one of the mufflers weigh? I ask because when I took mine off to pull the engine, it weighed a ton. I bet it was a solid 20/25lbs. My son even commented on how heavy it was. We talked about burning it out but I wasn't sure people did this on these. We have done them on old 2 stroke bikes before but never for a four stroke application.

What cart?

I bbq'd the 4 cycle muffler from my DS. It was a new(er) engine and when I installed it, after about 5 minutes (when the muffler got hot) it smoked like crazy, the muffler came from another engine that smoked a oot.for a very long time. Lot of oil build up in there... after bbq no more smoke.

Really the only time you should have to bbq a 4 cycle motor is if you rebuild an engine that's been smoking a lot for a long time, to clean out the unburnt oil. Otherwise, 4 cycle mufflers should be good until the day they rust to pieces.

2 stroke mufflers need to occasionally be bbq'd because you're directly mixing the oil and gas, so some of the oil is unburnt and passed through. In a 4 cycle engine this isnt the case, so there should be little, if any unburnt oil passing through to the muffler

[gunwhatgun]

Originally Posted by CP241

What cart?

I bbq'd the 4 cycle muffler from my DS. It was a new(er) engine and when I installed it, after about 5 minutes (when the muffler got hot) it smoked like crazy, the muffler came from another engine that smoked a oot.for a very long time. Lot of oil build up in there... after bbq no more smoke.

Really the only time you should have to bbq a 4 cycle motor is if you rebuild an engine that's been smoking a lot for a long time, to clean out the unburnt oil. Otherwise, 4 cycle mufflers should be good until the day they rust to pieces.

2 stroke mufflers need to occasionally be bbq'd because you're directly mixing the oil and gas, so some of the oil is unburnt and passed through. In a 4 cycle engine this isnt the case, so there should be little, if any unburnt oil passing through to the muffler

It's and EZGO TXT 2004 model. The engine was smoking. It is the one I am doing a big block swap on now.

[Dabble Inn]

Originally Posted by CP241

let us know what kind of a difference it makes in performance. I recently cooked the muffler on my kids little suzuki LT80 and that little thing was night and day difference.

After running it yesterday I can't say there's a night and day difference, But it did seem to accelerate a little quicker. So yes, I'm glad I did it