The solution is a simple fix. Remove the diaphram cover ( the one with the 4 small screws) and adjust the needle seat a tad lower. Your loading the low end up because it is set to high. On the Sach's 4.2;s the diaphram sit;s on top of the carb with the engine mounted inverted,and with the high needle setting,it will gravity feed through the carb asnd out the butterfly opening.

hope this info helps

Art