225 v-max did not run for over a year

Did not start till i drained full tank, replace lines all the way to the fuel filter in the motor, replaced fuel filter, checked pick up line in tank. having cutout issues and top speed is down,
it will start right up idle great and even jump out of the hole at first, but after about 100 yard starts to slow and even cut out altogether.
pulled fuel injectors there was a little debris in the little filter inside the injectors still no fix sit on the water about thirty min runs good for about 100 yards again

the year is a 1999 225 Yamaha v max any input will be very much appreciated

Sounds like you need to look inside your vst for a dirty suction screen and maybe some new fuel lift pumps. Some boat manufacturers use a pickup tube in the fuel tank with a screen in it. Dumb idea in my humble opinion but if you have one, remove it, and then trusting you have a nice boat mounted 10 micron fuel filter assy the random tank debris will go there. I have also seen the fuel check valve just after the motors fuel filter get very resistant to flow.

Thanks for the replay I did change the two of the three lift pumps, there is one behind the nine hundred dollar fuel pump that still need replacing.
I did locate the check valve right after the filter I will be replacing it. I am guessing that the fuel pump will be the next stop just trying not to spend nine hundred dollars so I am going to pull fuel pump and try to clean at last resort, it dose pump, but need to know how much PSI it pumps at.

Thanks again for the help,I did not think to replace the check valve, I will not know till i put it back in the water next week. but I will let you know how the check valve looks when I take it out

where and what is the vst dirty suction screen

The vapor separator tank houses the high buck fuel pump you referred to. You don't need to buy one but you may need to clean or replace the screen on it. Make sure you get a new seal for the cover. they rarely retain their shape. But I wouldn't go any further without knowing that there were no restrictions between the motor and the fuel source.

I am looking for the new seal and screen now, thank you thank you!

Don't forget to look at the fuel pickup pipe in the tank. If it has a screen on the end get rid of it and let the debris go to the filter.