I've seen posts in other locations on OSO. However looking specifically in the PQ forum. Since all hulls and setups are different. I have a 454 Magnum, single, that I've had for 5 years. This year, 2nd time out, I started experiencing, what I know now, is vapor lock.
I've seen a Mercruiser fix "kit", other misc fixes, including, not limited to: moving the spring in the VST, on the other side of the diaphragm; using a electric fuel pump; re-plumbing the gas lines; installing a return vent line; keep a cooler of ice to pour on the fuel rail; push in the release valve to release the vapor; lift the motor cover when you stop; install new air inlets/ scoops; my favorite-install an outboard fuel line pump.
I'd think with all the knowledge I've seen here, someone would have the tried and true fix... And open to a couple more funny ones.
This has happened just in the last weekend. No problems 4 weeks ago, the first time out.
Thank you in advance.

I have one.

I have never had a carburetor vapor lock in a boat. LOL.

I know, right...... I've seen so many "fixes" for this. At times, I wish it were car berated not the MPI....

Best fix: get rid of VST and install an aeromotive fuel system.

Just an fyi, and not saying this is your issue but something to keep in mind.10% ethanol fuel is more prone to vapor lock than pure gas. Also fall and winter blended fuel at the pump for cars if left in the boat to use in hot summer like weather in the spring can vapor lock more easily.

I started getting gas from an ethanol free marina. Is there a winter blend too for Ethanol free? I may have bought late season gas, and winterized. Already used 1/2 tank when I refueled last weekend. They said they had just got in the newest load, the week before.
Gimme Fuel. I saw someone on another forum doing that. I flagged it as they weren't completed with the install, and was going to post afterwords.