it is a huge pain. I verified everything on the stands when they were running. remove vaccum from pump and 30psi consistent on both motors. 22 with vac hooked up which. idle around 16-17 inchs of vaccumm.

UPDATE: filled with fresh 93 and still have the same issue. 30 percent throttle to hot start. if you run boat and turn the boat off. it starts back up immediately and runs great. even after sitting for a few min. This is BOTH engines.

note, this has happened twice after boat sitting for about an hour and half each time.

Did you pump out all of the old fuel before filling with fresh?
And, unrelated perhaps, but why 93 octane?

yes, pulled level sender and siphoned 45 gallons out. boat requires minimum of 91 oct. 28zx with scorpion engines

Ah yeah missed that part. Merc actually says 92 oct required.

FOR SURE, Im going out tomorrow. gonna try and do some starting tests here and there and see if it happens in 30 min, or 1 hour. get some real time frames. cause it very well could be vapor lock. want to try and rule that out. ill be out for 6-7 hours tomorrow.

Is it alcohol free fuel that you are putting in?

As a test Put a cold wet small towel on fuel filter separator when you turn them off.

The fact that you have to add throttle (open the throttle blades) to get them to start indicates it is mildly flooded. I would look towards injectors not fully closing and leaking into the manifold causing your symptoms. What caught my eye was the fact there was a 6 month gap between injector cleaning/flow testing and their first use. I have been under the impression that the injectors should be installed and used sooner rather than later after cleaning.