20.5 opposed twin stack exhaust.

I am in need of desperate help. On my 20.5 Briggs opposed twin. The stock muffler rusted off. I pulled the exhaust pipes from the ports and it is not threaded. The stock pipe and flange are so rusted I don't think they can be used. Has any one set up stacks on one of these. The exhaust pipes stick out at a angle towards the front of the tractor. I am wanting to put stacks with small mufflers inside to tone it down a bit from straight pipes. I have been trying to find flanges on line to get someone to weld up a set up stacks. If anyone has gone through this, your info would be greatly appreciated.

When I was laying bed last night I had a thought. I was thinking of welding a male pipe fitting to the flange. That way I can build off of it any way I need too. Has anyone done this?

building an exhaust without your own welder COULD get expensive, on my old mini buggy with a tecumseh 17.5 vertical, I welded one piece of pipe (called a nipple in plumbing) that nested just inside the flange to a 1" or 1 1/8" grade 8 washer (generally a grade 5 or 8 washer is thicker than a grade 2, IE cheapos) before welding it up I used the old flange to drill the mounting holes. I probably still have that thing on the old motor, from that I came out with pipe to something thin, like conduit or actual muffler pipe, but there is no reason you couldn't use a coupler or elbows to get you where you want to go with other nipples and connectors. Pipe and pipe fittings get heavy, so definitely need to figure out a support to keep you from breaking off the exhaust bolts area of the head. an exhaust muffler clamp from the auto store might get you where you need to be for support with a little ingenuity/planning.

if welding is completely out, they make a thing called a floor flange, I've never done this, but its basically a flange they use to attach pipe to the wall or floor, if you used a grinder judiciously and drill the mounting holes from the flat side, you hypothetically could make a exhaust flange without welding, the big issues I see here, the flanges have a taper to the outside top edge, and you only need like 30% of the metal your starting with, so theres alot of time involved in knocking one out, but if you have nothing else you can use, with a bit of time you should be able to make it work.

Thanks for the info. Once I get it out the sides I would like to put muffler on it then a stack. If I could get away with it, I would run the pipe into the muffler then hopefully find a stack that I could slide over it to cover it and clamp it on.

I use washers from tractor supply as flanges. They're pretty thick. Usually bowed somewhat from how they stamp them out, but not enough to mess up a seal. I generally put them so they are cupped away from the engine. I think the 1" ones fit the ports on most lawn tractor sized engines pretty close. Outside diameter is kinda big, so sometimes you might need to saw off an edge for clearance.

Another idea, almost like mr mods, but you can see i used the stock flaunges and welded bendy tubes to the flaunges and so on. So you can easily just weld some bent tubes that fit your liking for stacks to fit.




Ps, if you havnt run stacks before, ill let you know. A stack thats hood or neck height will stink up your clothes with exhaust fumes. Out of the 5 exhaust systems ive on my tractor, that was the most short lived version.