TOPIC:

I have a 2005 yamaha150 four stroke. Runs great until I throttle up. Get up to 5000rpm runs great for a couple of minutes then the RPMS start dropping to about 3000.
Changed filters changed plugs checked all wires everything else looks good

Thanks Irish Prince

try this
put vacuum meter and clear hose between engine and boat fuel tank no bubbles in clear hose and vacuum below 4 In or just try a portable tank see if problem goes away

Thanks Frank I will give it a try

You said you changed filters and this may sound silly but ensure the fuel filter(s) is/are in correctly. Some will fit both ways and have restrictive flow if incorrectly installed. Simple fix if that is the issue, they get clogged and sometimes will get replaced incorrectly and cause that very problem as the fuel gets restricted at higher RPM. Happened to someone I know about a month ago.

Thanks Netminder I will check it out hope one of the fixes can remedy the problem . Will keep everyone posted on my findings and what the fix was