I have installed two brand new Merc 3.0L I/o's in a 1977 24'sea ray. Both engines run great at idle and run great at higher RPMs but will not throttle up without bogging down and sometimes stalling. Slowly advancing the throttle works fine, only quick advances cause the problem. These engines have an HEI distributer with a separate coil. I have the Merc service manual and have followed the required procedures for setting the timing and idle mixture and the problem still exists. I have verified that the choke and accelerator pump are working properly. I have tried advancing the timing slightly and it didn't seem to make a diference. <br /><br />Everything is new from helm to prop, this includes wiring, fuel lines and filters, engines, gimbals, outdrives, trim pumps, everything except the fuel tank. The tank was removed for inspection and found to be in good shape and reinstalled. It did sit empty over the winter so some condensation may have occured. There are two separate pickups from the tank, one for each engine. Both lines have new water separaters/filters in addition to the filters on the carb. <br /><br />What else could I be missing? Is there some unknown trick for setting up these engines?
