So after i run the boat for 20 to 30 min. It develops a miss onvthe top end and will get worse as i continue to run the supra until it dies. It will strt the next day and do the same thing all over again...for the first 30 min the boat performs very well...no misses ect. Ive installed an electronic ignition and it is getting spark...new coil too...there is gas flowing into the carb..i installed a new fuel pump.... the plugs r new ...so there is fuel and fire ....help...!