I recently took my boat on our first trip and found it hard to start. When I did ge the motor started and in idle, it would reguarly stall when going into forward. To get the boat into action I had to have the revs extremely high which would see the boat dangerously launch forward. Once going it continued without a problem. A friend has told me that I should have the valve open on the fuel tank cap which allows air into the tank. I had this closed the entire trip. Does this have a big impact?