Re: mercury 225 outboard power loss
Check/change fuel filters then check both primary and secondary fuel pumps for pressure and flow.
Secondary pump pressure must be checked again at speed and under load, pressure falling off indicates a problem with either the 2d pump OR the fuel level falling low in the accumulator which could be either a weak primary pump or restriction thru the filter or line or fittings.
This is IF it is even fuel related
You could have a stator beginning to weaken at temp.
Test spark stone cold then test again at full temp, say after a hard run and when the power is beginning to fade.
Need to determine whether it is ignition or fuel.
Since I sometimes think bass ackwards, read this post from end to beginning.
Ihave a 1997 mercury 225EFI outboard. Recently had water pump trouble with the engine overheating badly. Replaced the water pump and Tstats and that problem is fixed only to have retarded timing at around 2500 RPM's. Any ideas???????