I have a 2 stroke Mercury 2.5 hp that has recently been dropped in the water. The motor used to run fine but now it won't start. I have dried the motor out and cleaned the carby, it's got plenty of spark, clean fuel and compression but it won't start.
One of things I've noticed is a lack of vacuum at the intake manifold, there is some there but it's not nearly are strong as the compression at the spark plug.
How strong should the vacuum be compared to the compression?