1977 V8 Mercruiser 898

[SalmonSlayer2016]

I have a Cruisers Cuddy Cabin 1977 with a V8 305 Mercruiser 898 motor. The motor starts great and idles great. When I accelerate to 3000 rpm it chokes out. We took the flame arrestor off and saw it choke out. We opened the gas cap and got to 3500 before it choked out. It restarts right away. Any suggestions? I am illiterate when it comes to motors and fixing them.
Andy

 

[Bondo]

Any suggestions?

Ayuh,..... Welcome Aboard,.... She's Stravin' for fuel,.....

Start with checkin', 'n changin' the fuel filters,....

Could be crap in the tank, bad valve, bad fuel pump, or bad carb,....

Run it on a clean pail of gas hooked right to the fuel pump, to by-pass the boat's side of the system,....

 

[SalmonSlayer2016]

I did change the fuel/water separator. Thank you for the tips

 

[Pete104]

That ain't the only filter you got. The tank has one & the carb. Try running as "Bondo" suggested. Use an outboard tank, though. It won't matter if it's got oil in it.