So far I have removed the muffler and run it with no noticable difference. It turns out the muffler is brand new and still clean inside. The blue flame from the exhaust was pretty.
The fuel tap was fitted backwards but was still allowing some fuel to flow through at a reduced rate. I noticed some rubbish had shown up in the float bowl after the run so I'm soaking the carb at the moment. It doesn't have a fuel filter which can't be good. I haven't done a proper compression test but it feels really good when turning it over by hand. Doesn't seem to be leaky.
