I have a true world marine 28.6" 300 HP Yanmar 20Y old. Boat accelerates to 20mph engine dies exhaust alarm for raw water lights up engine still runs but s runs at idle. I attempt to throttle up again slightly over 2000 rpms loss of power alarm sounds again. This issue starts after about 1 hour of operation. some one recommend fuel starvation I cleaned out Racor 900 MA fuel canister changed 30 micron filter along with fuel engine filter. I have no idea what's causing this problem. I plan on introducing a 12 gal poly fuel tank and connecting it to the engine filter to by pass the boats 170 gal tank and rancor filter. Would anyone out there know what can be causing the problem.