Briggs Low Tone Muffler Failures

[TWG1572]

In the last 5 hours of operation, I've had two new B&S OEM low tone mufflers fall apart. Basically the weld? fails where the outer housing is connected to the pipe coming out of the engine. I end up with that whole housing falling off, and just a perforated straight pipe sticking out of my engine. I'm perfectly OK with having my Briggs 8hp I/C flat head straight piped, but my neighbors and wife are going to disagree.

Two of the same failures in five hours tells me I've done something wrong. After the first failed, I was certain to only use the "pipe" portion to screw the muffler into the engine block. So the outer portion hasn't been stressed from wrenching on it.

What I have noticed is that both mufflers seem to keep working loose. I crank on the tightening ring as much as I can, but it always seems to back off.

So what's going on? I can't imagine I have two defective mufflers from two different suppliers. Both were OEM B&S

Pic attached for clarity on the issue. Red = failure point.

 

[spasm3]

Can you have someone mig weld that area? Sounds like a poor design. Probably newly outsourced to china. I might use some anti-seize so you can tighten it down with less force.

 

[dave123]

Buy Honda neighbors and wife will love you.

 

[TWG1572]

Originally Posted By: spasm3
Can you have someone mig weld that area? Sounds like a poor design. Probably newly outsourced to china. I might use some anti-seize so you can tighten it down with less force.


I could, but my welding cost is going to equal about three mufflers. My first muffler that went was an ebay NOS one that was pretty vintage, so I'd like to blame the Chinese but I'm not sure that would be fair. I did not use anti-seize but will on the next one. But I'm not putting any force on that area when installing, so I'm thinking it may be a different root cause for failure. Could be wrong though.

 

[TWG1572]

Originally Posted By: dave123
Buy Honda neighbors and wife will love you.


I hear ya, but not an option. This is on a Troy Bilt horse. I rebuilt the engine last year. Bored out, reground valves, the whole nine yards. It's not going anywhere.

 

[spasm3]

I don't know what you paid for it. It might not be worth shipping. I'd mig it for you.

 

[spasm3]

I think i found the listing on ebay. If thats it, it's a weak looking design. Not sure its oem.

 

[TWG1572]

The picture I posted was just one I got from the net to show the design. Sorry if that was confusing! So I'm with you that the one in the picture is not OEM. Mine are both B&S - came in the box and have the logo stamped on them.

It looks like I can buy another OEM one on ebay for $9.99 so it's probably not worth the shipping. I do appreciate the welding offer though!

 

[JTK]

Geeze, I haven't seen that style muffler in a long time. That's a lot of mass dangling off that pipe nipple to deal with the vibs. That would need to be a pretty sound weld to hold up.

 

[jhellwig]

I would say there is a vibratiron tearing it apart.

Look at Briggs website maybe there is a bolt on one that would work. The bolt on ones are usually quieter also.

 

[loyd]

Can you install some kind of brace to help with the vibration?

 

[bubbatime]

IF OEM keeps failing, look for an aftermarket one from Oregon, Stens, etc.

 

[jayg]

Or put a Supertrapp from a dirtbike on it and make more power!

 

[TWG1572]

I'm starting to think that maybe the cause of the failure lies in the muffler continually working itself loose. Once it's a bit loose it really starts vibrating.

How would one go about making sure the next muffler stays in better? What the picture doesn't show is a nut on the pipe nipple that you also tighten against the block. Theoretically, that should keep the muffler from working out. YMMV. Maybe I could locktite that nut?

 

[NHGUY]

A Briggs shouldnt run that rough,you may have an engine about to explode or somehow the balance is off.

 

[TWG1572]

Originally Posted By: NHGUY
A Briggs shouldnt run that rough,you may have an engine about to explode or somehow the balance is off.


I don't know if it's vibrating any more than any other Briggs engine. It runs smooth, not bouncing around or anything. Now I may be completely wrong, but it doesn't seem like I've got a balance issue or it's ready to fly apart. But I don't claim to be much of a small engine mechanic either.

I am going to take a look and see what other mufflers might bolt on to the block. That may be the easiest way to deal with this.

 

[JTK]

TW, can you run a standard hotdog type muffler on it?

 

[bubbatime]

Try the heavy duty, non low tone muffler

http://www.ebay.com/itm/Briggs-Stratton-...E-/160902931876


It uses a standard 3/4" NPT thread. You can ad a pipe, a 90 degree elbow and clamp on an auto style muffler if there is room.

http://cd3wd.com/data/1003_core_vet_voca..._en_121200_.pdf

Or, screw a 3/4" NPT pipe into the exhaust, run that into a 3/4 to 1 inch adapter and run the 1 inch muffler. Should be much sturdier.

 

[TWG1572]

JTK and bubba - I think either of those would work. The 3/4 pipe thread is what i need.

Bubba - I'm thinking yours looks like a heavier version of what JTK posted? Or are they the same?

I also see that the IPL for my engine lists a couple alternative mufflers. A couple are the flat box ones that bolt to the side of the block. That may also do the trick.

Is there any issue with changing muffler styles? I can't think of any, but don't know how they pick a muffler to begin with.

 

[JTK]

They're the same muffler.