stalls at idle when warm

boatman37

So our boat sat for 3 years when we bought it and last year we had fuel issues. Had about 20 gallons of separated fuel so siphoned it all out (100% empty). Still had trouble so I rebuilt the 2 bbl TKS carb (turn key start). Carb was a mess inside. Boat ran good the few times we had it out after that. Today we went to the fuel docks and added 35 gallons of ValveTech fuel (had about 20-25 gallons of ethanol free in it before that). Went for a short no wake cruise then headed out to the Ohio River. Got on plane and went about 1/2 mile up river then came back about 1/2 mile the other way and went to drop anchor. I always back it down slowly and no abrupt neutral stops. Got to about our anchor spot and went to walk out to drop anchor and heard a couple of beeps then the engine stalled out. Tried to start it with no luck. Dropped anchor for about an hour or so then started it right back up and came back in with no problems. I was on plane most of the way back then slowly dropped it down in increments until I was back at the slip. Dropped it to neutral then reversed into the slip then back to idle at the dock and it was fine.

Boat is a 2006 Crownline with a 5.7 Merc TKS (turn key start) 2bbl Bravo III. Fuel separator was new after I siphoned the tank last year.

Seems to only do it when engine is up to temp and after a run on plane. If I stay in the no wake it seems to be fine all day but haven't 100% tested this.

Going to replace the separator but doubt that is the issue. When it stalled and I tried to restart it may have started if I had pumped the throttle but I didn't. Normally I don't touch the throttle to start it (point of TKS system).

Engine has 228 hours and had new plugs installed about 20 hours ago. Don't think I did the cap/rotor but seems to be a fuel issue.

Any ideas? It is not fuel injected so no IAC valve but does have electric pump