Cutting and welding riding lawn mower muffler pipe

SpotsyMatt · Oct 25, 2015

Hello there,

I have a Husqvarna riding lawn mower. I replaced the Kohler engine with a Briggs engine (was a few hundred $ less and locally available) and it seems to be working OK but I need to relocate the muffler.

The Kohler's muffler was located below the engine and used a pipe to route it down to the muffler.
The Briggs engine's muffler is on the side and is in the way of the hood. Here's a pic of those:

I've not done any welding but have the inclination to do it and time to learn. Admittedly, I've got a lot to learn about it - I've watched a lot of videos and read a book but that doesn't mean much, of course.

Anyhow, my thought was to take the Kohler pipe and cut it with my metal bandsaw and then rotate and reposition it to the correct angle and weld it back together and use it in place of the Briggs one.

Any thoughts/advice on this would be helpful. I was looking at some inexpensive welding machines at Harbor Freight that would run off my 20 amp circuit.

Thanks,
Matt

Tractor Seabee · Oct 26, 2015

It would be a O/A #0 tip and coat hanger wire job for me. I think O/A is easier to learn fast than those little MIG rigs. The price of HF's little O/A kit is in line with their little Mig units. to bad you are 3K miles away or I would do it for you.

Ron

SpotsyMatt · Oct 26, 2015

Tractor Seabee said:
It would be a O/A #0 tip and coat hanger wire job for me. I think O/A is easier to learn fast than those little MIG rigs. The price of HF's little O/A kit is in line with their little Mig units. to bad you are 3K miles away or I would do it for you.

Ron

Thanks Ron for the opinion and advice. I think I'm going to try the Oxy acetylene route later this week when I have a little time.
My late father-in-law had a O/A setup in his garage and I'm going to grab that and practice a bit on some scrap metal first.

Matt

pat32rf · Oct 29, 2015

As a beginner you will probably get a satisfactory job quicker with OA than arc, mig or tig...Especially on a used exhaust pipe....

KubotainNH · Oct 29, 2015

I have an HF wire feed welder and it does great on exhaust pipes. Pretty easy to learn too. I've beat that thing into the ground and it stills works well. The flux core wire that comes with it is kinda crappy though.

KubotainNH · Oct 31, 2015

Have you thought about buying the pipe itself? Maybe one like in the link below? Most of the pipes just twist out of the muffler. The picture is one I have on a junk mower, looks like it is similar to what you need.

17 5HP Briggs and Stratton Exhaust Pipe | eBay

Sodo · Oct 31, 2015

You are trying to make this B&S installation a clean install by plumbing it to the original exhaust. I would do that. You are lucky they come out in the same neighborhood!

But you intend to learn welding on this thin pipe, of which you don't have any backup material (a spare exhaust pipe ! ). If it turns out to be birdpoop because of factors like "first weld" or "aluminized/contaminated material", or other factors, then you could have a clean modification marred by birdpoop.

I would not use a bandsaw. I'd use a hacksaw, or 4 1/2" angle grinder with a thin cutoff wheel. You want to cut the MINIMUM pipe possible, leaving material for do-overs. A bandsaw is the wrong tool for this cut. Of course there is a slight chance it will cut the pipe in both optimum locations.

Is it possible to run the original B&S exhaust as it is, until you get good at welding? Also looks like you will need a longer pipe to reach the HusqV muffler. It would be useful to locate a "bend" (scrap?) that is larger diameter than both, so you could do "overlap" joints on each. Many many ways to do this. If you have an eye for scrap, and a place to search for it, and time to practice it can come out nicely. You could do the overlap, with slots, and clamp it (until you get better at welding). That pipe on eBay looks like a GREAT find!. Maybe run it as a straight pipe until you get set up, or your wife kills you.

Those exhaust manifolds look to me like they are aluminized ( a coating ) to make them resist rust longer. Maybe someone who has welded aluminized exhaust pipe can comment how it welds.