problems i cant figure out--- my 50 hp johnson first problem was when i attempted to go to full throttle the engine would fall flat would not accelerate unless i pushed the inrichment button, the engine would pickup as long as the inrichment was used. many test were performed and as a result all fuel lines, v.r.o., fuel filter were replaced. after testing in the water there was some improvement, but not a 100 percent. after that i noticed that the engine acted like it was loading up and and does not want to idle at times. as a result of this the carburetors were rebuilt, new theromstat, the linkage was all checked and adjusted with little to no improvement, when the engine died in most cases it would restart idle for a short period then die. the low speed mixture screw is out about 2-1/2 turns. today i hooked up a different fuel source nothing changed, one thing i did try was to seperate the carburetors buy removing the link between the two. the engine appeared to maintain a idle, but when opening the throttle on the top carb. the engine would miss pop and smoke, doing the same thing with the lower carb. it would accelerate fine , no smoke and would idle. when the carbs were rebuilt they were completely disassembled , passages where blown out with air . new kits along floats were used. can anyone offer any help?