don't know the history on this...but with cleaning the idle jets....great.......did you also clean out the tank and make sure you are getting clean fuel into the carbs??
if not you may have just wasted your effort...
top down process
tank, tank/petcock filter, fuel line, inline fuel filter ?
all clean - proceed to step 2
clean carbs.........ALL JETS....not just the idle or air bleeds............check for free flowing fuel into each one, and make sure the float needle/jet works....floats roughly the same height or the same fuel volume in each??......proceed to step 3
reset ALL carb idle/mixture adjustment screws to standard settings - whatever they may be ......step 4
make sure all linkages are working properly, slides are working smoothly.... step 5
make sure all manifold clamps and inlet rubber boots are sealing properly...no cracks or looseness....step 6
if everything else is within reason .......timing/valves/spark/spark plugs/compression/clean air filter....it should start and run............good luck...keep at it