I've been having trouble getting the boat to start/crank. Initially I thought it was the neutral safety switch, but I now have that removed so it's definetly not that. The batteries are charged and cables are tight. It is an intermittant problem. I have noticed a few odd things. Once, I noticed it started but there was smoke/burning smell from the area where the mercathode controller is housed (front left side of engine). Another time, I heard two loud cracks or pops after it started. Any ideas?