I have a 135 merc. that I can't figure out!..the problem is.....when I run the motor on the hose, it starts great and runs good. It idles a little rough, but I had a mechanic look at it he said the compression was good, timing was set, and it ran a little rich, but adjustment was made and it doesn't smoke half as bad...BUT...when I get it in the water at the lake, its hard to start and after it does, it runs great, up until I shut it down. When I try to restart it, it acts like its not getting enough fuel, but the bulb is full. I have to choke it several times, and keep it in neutral accelerated to get it going. So far I have rebuilt the carbs, fuel pump, replaced the fuel filter and primer bulb. Could the water pump be a factor, or does this sound like a electrical issue? I'm at a total loss!....oh and I always put premium fuel in it...any help would be great! Thanks..