I was installing a Pitts style muffler onto a DLE-30. However, I noticed the exhaust port shape in the muffler didn't match the head port shape. Being a former motocrosser, I broke out my handy Dremel and fixed the problem.
The stock DLE head has arches in each port wall, except one. You can see from this first pic the problem (I actually took this pic after I was already started, sorry! But you get the idea)
Middle pic is partway through, and the final pic shows the matched port. The gasket matched the cylinder head on the DLE perfectly already, so no trimming was needed there, and I was able to use if for a cutting template.
On such a small motor, I really didn't want a port constriction right at the start. This is an easy mod. The muffler was cut with a rectangular port that is more "generic" so it probably fits other 30cc gassers.