gt500 ?

[quark77]

been enjoying the sun on my 380,550,750 ! but sadly not on the gt500 ,had a prob where as it would run on both then only on to one (usually on choke ) stripped the carbs ans found blocked pilot jets that were too mangled to remove , so different carbs new pilot jets , starts easy but with black oil leaking from l/h header pipe , again starts on two and then r/h dies , had new coils , electronic ignition set up any pointers would be gratefully received