1996 Merc 5HP 2 stroke - used first couple times this season worked fine; new gas/oil mixture and oil lower unit; stalled last time out, changed plug and gas (again) just to be sure... idled but would not throttle up. Took in for service and was told diaphram in fuel pump was unseated so they replaced, I was advised to install new, so installed all new with rebuild carb kit, but now, it wont even crank... has spark and getting fuel to pump. I tried to adjust mixture a couple turns and may now be off the mark - is there a way to test or adjust to start? Any other suggestions?? I'm stumped.