Glad to hear that was your issue. I have the same setup in my 2006 Rinker 226 and my problem was the fuel booster pump. There was a service bulletin on this through merc. Since I had the fuel booster pump installed I have had no issues.

Hmm, I've been having similar issues with my VP 5.0 GXI. Sit in a cover for an hour on a warm day and it will not immediately start unless I advance the throttle, and/or it will start right up and spit, sputter, and pop trying to get on plane. Let it idle a bit then it will run fine. Seems to happen only on warm days with less than a 1/2 tank of fuel. Sometimes I can hear the fuel pump whine when it's having issues. So either I have a pump dying or a vapor lock issue.

On Saturday, it cranked a while to get started, as we were idling out of the cove it was having a hard time staying running, I advanced the throttle, then it was popping and bogging down, I put in neutral and it started idling at 2500rpm, slowly went back down to normal idle, then ran fine.

Sunday, I filled the tank and it was a much cooler day. After sitting in the cove for an hour, she fired right up and ran fine.

Jeez, I'm getting flashbacks to the 60's when vapor lock and other hard-start issues (or warm-start) were fairly common.

We would never accept that as normal maintenance nowadays on cars, why is it apparently so common on boats?

Well, some boats still use carburetors, for one thing. I realize RX's doesn't have one, though. But the environment for a car engine is about as different as possible. On a boat, the heat has nowhere to go. On a car it's got the whole underside to get out of of. And a lot of air passes over a car engine, but not a boat engine. Then there is the added possibility of water in a boat. It all leads to needing to maintain a boat a lot more carefully than your car.

Now there are just some things that break (like fuel pickup hoses) that shouldn't. But remember, there are far fewer boats built every year than cars, so the parts makers may not have made as many parts in 10 years as a car maker makes in 1. So problems may not show up as fast, or be as quickly corrected.

Yet we get the privledge of paying lots more for boats and parts.

Hey, you gotta pay to play!

Topeka, I'm having a hard time understanding how a cracked pick-up is causing your trouble. It seems to me if the fuel system is sucking air from the crack, which it would do all the time--hot or cold, the boat should be giving you problems from the first start of the morning--not just after it gets hot.
For your sake I hope they did find your culprit, but things aren't adding up in my simple mind...

Just a thought, and it is only a thought. Fuel pick up always introduces small air bubles into the line. Not enough to cause loss of prime on the pump or impact running of the motor based on boating style.

After running for a while, motor shuts off and air bubbles expand due to heat and now it loses prime on the pump and can't get running.

Again, I could be totally off base.

IMO boat engines don't get hot enough to cause vapor lock (gas vaporizing in the fuel line). What sometimes passes for vapor lock is gas boiling in the carb, which can cause the same symptoms.

The reason the cracked pickup would cause the trouble is because the fuel in the line can drain back into the tank. This results in air in the fuel line, which is a mirror image of vapor lock. And I've read what many folks here have said about air in the fuel filter/separator...

I just find it strange that I only have the starting problems after the engine has been off 30+ minutes on a hot day. If it's over 85 out it almost always happens, under that it never does.

My VP 5.0GXI runs 175 degrees. That's quite a bit of heat.

I might have the dealer do some diagnostic work in the fall. The problem has been getting worse, so maybe something is wrong with the fuel system.

JMO...Since it is fuel injected, I would be looking at the ISC motor real close. Heat build up after shut down causing it to bind up and not allow for proper movement of the spool valve causing a hard start and or ruff idle. After replacing mine I now relize that it was going bad for a while but I didn't pay close enough attention to the signs. I would be idleing down a nowake zone and every miniute or so it would surge. Not alot but just enough to hear. Soot on the transum tunnel every now and then. Thought it was from pulling tubes and the stop and go. The $90 part is real easy to change. I'm not sure a scanner would pick anything up until it fails.

RX, I take it your engine is fuel injected? If so, you can do a little diagnostic checking yourself. You'll need a medium sized phillips screwdriver, and a sacrificial rag. You'll need to locate the schrader valve on the fuel rail, and remove the cap...

Next time you've sat for 1/2 hour on a hot day, remove the valve cap, bunch up your rag in one hand (wearing gloves wouldn't hurt), hold the rag above the valve, then press in the valve QUICKLY with the screwdriver...

You SHOULD get a good spray of gas out of the valve. If you get a small dribble, or nothing, then your fuel line has lost pressure (which it shouldn't do for hours). This could indicate a similar problem as tumbleweed's, or a bad fuel pressure regulator, or possibly a bad check valve in your fuel pump. It could also indicate an injector that's leaking down, which would be indicated by lots of black smoke when it finally starts.

All I can think of for a reason why it only happens on a hot day is pressure buildup in the fuel system from residual heat, which could be the difference between a sketchy check valve or regulator holding pressure, or not...