What was the pop off on the carbs ? Might look and making sure they are still synced. This can be done with some .001 appx 1/4 wide shim stock or any thin, narrow feeler gauge to check the distance between the butterflies and venturies, or use the instructions in the manual with a depth gauge. Can get a cheep one at harbor freight. Pilot/low speed screws should be at 1 3/4 out. Main jets should be 165's for altitudes up to 6600ft. If you noticed a power loss in mid to upper throttle with the 165, then leave the 160's, but if now power loss was evident, use the 165's. You don't want to go lean.
Check and make sure the pick tubes in the tank are clear, all fuel lines are in good shape and tight (might be getting a slight air leak), might just go ahead and replace them. Using the manual, make sure all the needle arms are at the right height and are at the same height. Make sure the pulse line is good and not leaking. Might put new zip ties on it to be safe. Make sure the inlet filters in the carbs are clean. When was the last time you put new gaskets and regulator diaphragms in the carbs ? Again, it still might be the fuel pump, but need to eliminate everything else first.