Motorcycle Repair: 1982 cx500, rubber diaphragm, petcock

Question
I have an issue on my bike where sometimes when I accelerate hard it dies out around 4500 rpm an acts like it is starving. But then I let out of it an it will run fine. We have gone thru an cleaned an resinked the carbs twice to make sure that wasnt it. An now I am at a total loss as to what would cause it to only happen once in awhile.

Answer
Two things to look at. The slides in the carbs are not moving up and down in the bore easily and stick part way up or there coud be a pinhole in the rubber diaphragm. The other problem is that the fuel is not keeping up with the demand and it is restricted in the petcock strainer coming from the tank.You may have to clean it,as the factory does not put any inline fuel filters from the petcock to the carbs. There is a screen on the pick up tubes in the tank and eventually plug up.