Muffler bolts thread issue

[wing0]

Hi all,

Got a 5HP B&S engine that my father has been using for close to 20 years now.
Still runs fine after I cleaned up the spark plugs, change the oil and clean the air filter.

However, when I started it up 2 weeks ago, I noticed the muffler was shaking excessively against the cage that protects it.
The muffler looks like the following:
Muffler For Briggs and Stratton # 490547 692038 35-027

I thought the bolts got loosen so I tried tightening them.
However, the real issue is that the thread holes where the bolts tightens go in are completely gone.

Due to the age of this lawnmower, I am not looking for expensive repairs.
I just want to get the muffler back on tight so we can run it into the ground.

Would something like JB Weld work in this case? Or any other suggestions?
I was thinking another way is to use a bigger bolt, but that will require some drilling on the muffler to enlarge the holes too.

Thanks in advance.

 

[Fish]

Look at the hole that the muffler covers, there should be pipe threads there. Go to a hardware store, they should have a selection of cheap mufflers that will screw in the hole, real cheap!

 

[wing0]

Look at the hole that the muffler covers, there should be pipe threads there. Go to a hardware store, they should have a selection of cheap mufflers that will screw in the hole, real cheap!

Thanks for your reply.
However, the exhaust hole does not have any threads. The muffler is held on by the two bolts.

 

[Fish]

what are your engine's model numbers?
look again closely at the hole too.

 

[wing0]

what are your engine's model numbers?
look again closely at the hole too.

I'll get the engine model number later when I reach home.
I did check the hole and it has no threads.
The other side of the muffler: http://www.beurier-richard.com/boutique/images_produits/echsil28-z.jpg

It's a smooth lip that goes into the hole.

 

[Fish]

Well of course it is!!!! The bolt on mufflers don't thread in, but Briggs was good enough to leave the threads in on their L-head engines, so if the bolt on mufflers ever got boogered up, then you could always go back to the old trusty screw in muffler. They did not do that with the newer OHV models, which I am assuming you don't have.
I guess Briggs may have made a few blocks with no pipe threads in them, I must have not come across one yet...
But the pipe threads of course will be coked up with a lot of carbon. But if they are not there, go to a plumbing supply store and buy the $8 pipe tap, and then by the hardware store for the $4 muffler, and you still will come out quite cheaply.

 

[reynoldston]

The bigger bolt will be your cheapest way to go. Other then that a thread insert like a Heli-Coil. You should be able to buy a kit for around 25 dollars.

 

[Fish]

Yeah, well toward the end of the l-heads, they might have stopped tapping threads for the backup muffler, because there is not
a lot of "meat" there for bigger threads or a helicoil. That was always my biggest "beef" with the OHVs.... You had few choices..
Helicoil or new head.....