I stopped using gaskets on my gassers for this very reason. They just don't hold up. I started by making the header flange flat by sanding it with the paper on a plate of glass. Usually the welding process warps the flange. The engine side is usually OK unless your muffler/header has worked loose and ate through the gasket and was banging against the engine case. Make sure the surfaces are clean, I use acetone for this including the tapped holes. Put a thin layer of Permatex orange high temp RTV on both surfaces and bolt together with red locktite. The red locktite can be stubborn to remove so usually I will hit the screws with a 35 watt soldering gun to heat them up before trying to loosen them.


As for the backward starting, Usually it's because then engine is over primed. Perhaps with a different starting sequence. It's common to flip a gasser with the choke on until if pops and then floods out and quits. Maybe try to start by choking for a few flips short of popping and then try with the choke off. More run time, tuning and familiararity may just fix that one.