Got this boat out over the weekend after it had been seting up for two years.This motor does great for a few minutes then it has a slow loss of power while throttle is fully open.Already purged old oil and gas out of lines prior to this and it does seem to be oiling O.K. It idles great and it revs up O.K. using the idle lever.It seems to be when its under a load.Someone told me it could possibly be the fuel pump.If so what would be the proper way to check it?