Exhaust Flange for Honda GX390 Small Engine and clones

thingiverse

This is a custom exhaust flange designed for Honda GX390 clone engines and similar big-block Hondas or clones. It's perfect for building a custom exhaust system on small engine-powered go-karts or ATVs. To assemble it, you'll need to cut out the steel plate using a CNC plasma cutter or a similar method. I created this design after realizing that buying one would cost around $10 - an excessive price for such a simple piece of metal. Fortunately, as someone who works in IT at a metal fab factory, I had access to scrap metal and a CNC plasma cutter, allowing me to cut out several flanges from discarded material that would have otherwise been recycled. When it comes to the thickness of the plate, what matters most is the hole size and spacing. For this particular design, 1/4-inch plate works just fine. If you need a digital template, I've also uploaded an SVG file in the correct scale. The center hole measures 1.25 inches in diameter. You can use this as a reference point for your own custom exhaust system build.