2003 vmax 150 stalls after idling for a few minutes

Hey guys. Been lurking for a while but this is my first post. I have a 2003 Yamaha vmax 150 that has a stalling problem. We took it out last weekend and ran about 10 gallons through it and it runs WOT great, but when I idle for a bit or putt through the no wake to the ramp, it will stall. It typically starts right back up no problem, but this time it stalled and I had a lot of trouble getting it started. I pumped the primer bulb and it was hard, but gave it another pump anyway. After about 10 tries, it gave it a long starter pull and it finally started. Gunned it and then put it on the trailer. Not sure where to start. Is there a list of things to check or maybe a sticky that addresses these issues? Drained the fuel, added fresh 100% gas. New fuel filter and plugs. No changes. Thinking maybe I have some old fuel line letting air in somewhere? Any ideas?

seems like the fuel/air mix might be wrong. If it has them, try cleaning the carbs through and make sure that they are all in working order.

does it smell strongly of fuel when it stalls?

Not that the have noticed, but it the sound definitely changes leading up to the stall. Not sure if it is a lean or rich condition, but it sounds like my nitro rc cars when they load up on fuel when idling for too long. Do gasoline carbs act the same way? I would think you could idle “forever”

It has carbs, 3 of them. By cleaning, do you mean a seafoam or carb cleaner or actually take them apart and clean them?

Here is a video of the cold start and stall. Does it sound odd to anyone?

Drained the fuel and put in fresh fuel and it ran for an hour in the yard on earmuffs. Took it out on the lake and it stalled on the dock. Ran it for about 30 minutes and it started stallin, but would fire back up. Then, after a full throttle run, when I came down to idle it stalled and wouldnt start back up. We had to be towed back to the dock. Any ideas?

It is in the shop and so far I am on the hook for 8hours labor and they can’t figure it out. They found about an ounce of metal shavings in the fuel tank which they can’t explain. More new plugs, filter, and lines. Cleaned tank. Then 3 rebuilt carbs. Still stalls. It will run for 20 min or so in the water but when you come from full throttle to idle, it stalls.

Lost faith in my mechanics, so I picked up the boat. Still not fixed, so decided to throw parts at it. Replaced both fuel pumps and installed a new fuel lin/primer bulb. Also installed a fuel water separator. Ran it on the lake for 2 hours last night. Stalled 8 times, but started back up every time. Ran for 1 hour at 1200 rpm with no stalles. Seem like if I try to cruise at 2500 rpm it will lose rpm and then stall. Not sure if it is loading up on fuel or running lean, but once I see the rpm start to drop, I can give it a bump on the throttle to keep from stalling, sometimes. I can also cruise above 3200 rpm for an extended period, but going back to idle causes a stall. Any other ideas? Have 3 carbs. Does this sound like a carb issue?

I rebuilt all three carbs with new floats. It is running perfect. Looks like someone previously rebuilt the carbs and did t adjust the floats to factory spec. Problem solved.