2005 40hp 4 stoke EFI Hesitation

[nativejax]

Engine serial:1B019138
2005 ELPTEFI

I am having hesitation if I go from having the motor just in gear to a quick acceleration. Motor does not die, it just pauses for a split second and then takes off. Motor idles great and runs excellent. It also accelerates with no hesitation if I just go through the acceleration easy and steady.

I have done a 100hr service which included changing the plugs and have them properly gapped. I am also now running ethanol free fuel where as the previous owner was not and the motor only has 167hrs so it would sit for periods of time. I have also changed the fuel line, external water separator as well as the fuel filter on the motor. I know sometimes there are hidden filter screens on motors that can get clogged but have not dug much further that what I have done. I have a gut feeling it is a fuel delivery issue but I am not a mechanic.

[EuropeanAM]

Need to monitor fuel pressure and see where it is at:

-At idle

-UNDER ACCELERATION

-15/30/60 seconds after engine shutdown.

Don't overlook the injectors- they are extremely low-volume injectors, and often suffer from restrictions due to debris (or congealed fuel).