Went to ivie this past weekend, boat started fine at the ramp in the morning and ran fine. Later in the day after running from one area to another and fishing for a while the motor was hard to start, the primer bulb would be empty and would have really have to pump it for a while to get pressure back in the bulb. I replaced the bulb earlier this year and don't think that is the problem. Talked to some other guys that were having the same problem, it was pretty hot on saturday and thinking maybe the heat had something to do with causing the problem, like having a vapor lock. Never had this happen before. once I got the motor running it ran great. Anybody have any ideas or experienced a problem like this?

Didn't mention motor is a 97' mercury 225 EFI

There should have been enough fuel in the VST tank to fire the engine. Even if the manuel fuel pump valves was not working correctly, that should have not caused a hard start problem. I would look more at a voltage drop from the stator, due to the age of the engine and the extreme high temperature. The stator could be heating up while being parked for a few minutes and not produce enough power at cranking to excite the spark plugs. Once you start cranking on the engine the flywheel exhaust the ambiant air around the stator and in turn cools it. Once it drops a few degrees, more electric is produced and in turn more spark. This is usually quite evident if the engine hits a couple of times right on initional cranking after setting for a while then dies and won't keep running. The switch boxes were energized and setting idle, then de-energized when you kit the key and not enough electric produced by the stator to re-energize immediately. Hope this makes sense to you. but I would be looking at the stator 1st.

Not shure if vapor looking was some of your problem but I have been concered about this with ethanol, as it lowers the boiling point. I saw this at Amistad last Sunday. We went to move around noon, on start up the 250SHO spit and sputtered a little before clearing up. It was HOT out.