HELP 225 efi dropping rpms

[Dead Eye]

merc 2002 225 efi
When i go full speed the motor drops rpms. Seems like it wants to stall. I can idle speed fine. it is only when i get up on plane it drops in speed.
Changed water separator, fuel filter, even pulled the fuel tube from the tank to check it out. The vent to the tank is clear. Even has new plugs. Fuel was treated when it was winterized last fall. When the rpms drop it seemed like a fuel issue. Pumped the ball. It collapses and wont expand until I put the motor in neutral.
this is a new problem boat was running great three days in a row till this happened.
Thanks, Dead Eye

 

[Dead Eye]

Re: HELP 225 efi dropping rpms

Anyone? i'm on vacation and need HELP.
Thanks, dead eye

 

[Ed R]

Re: HELP 225 efi dropping rpms

Fuel pressure!!! Your motor has a filter in the VST tank that gets clogged though the years, that no one ever ckecks, or services. You can ckeck it with a fuel pressure gauge, if your (handy) If not, bring it in to a dealer, and TELL them you would like them to service ALL the EFI fillers. I do it all the time, with todays bad gases! good luck, ER.

 

[Dead Eye]

Re: HELP 225 efi dropping rpms

Where is the Vst tank?
I pulled the fuel pickup out of the tank and the screen was clear.
Thanks, Dead eye

 

[Ed R]

Re: HELP 225 efi dropping rpms

The VST tank is bolted to the side of the motor, It a work out to remove, you have to disconnect, fuel lines, vaccum lines, and fuel pump wires.But it is the heart of the system!

 

[Ed R]

Re: HELP 225 efi dropping rpms

Where are you located?

 

[Dead Eye]

Re: HELP 225 efi dropping rpms

in Ocean city Md. right now
Dead Eye

 

[Dead Eye]

Re: HELP 225 efi dropping rpms

Could this be a fuel pump gone bad?
Dead eye

 

[Ed R]

Re: HELP 225 efi dropping rpms

No, the pump filter is restricting fuel flow, it would run great at low RPMs right?

 

[Dead Eye]

Re: HELP 225 efi dropping rpms

it does run fine at low rpms. only when i lay into it , after i get on plane it dies. not right away but soon after on plane
thanks, Dead eye

 

[Ed R]

Re: HELP 225 efi dropping rpms

TO be sure, run motor off of a portable gas tank, to rule out boat tank, filters,check vavles,etc. I do trouble shooting work with mercury marine on Long Island.

 

[Dead Eye]

Re: HELP 225 efi dropping rpms

Thanks Ed. Ill Run a portable tank an check back tommorow.
Dead eye

 

[Ed R]

Re: HELP 225 efi dropping rpms

Ocean City !! i raced there (offshore power boats) hung at the (purple moose!) etc. I will ckeck you at 5 tomorrow, Ed.

 

[Dead Eye]

Re: HELP 225 efi dropping rpms

Unable to follow up on the problem. Family obligations. Wasted 2 days tring to get the boat up and runnning. I will post back when I do the further tests.
Offshore races are great but I mosrly fish. also the purple Moose rocks.
Dead Eye

 

[Ed R]

Re: HELP 225 efi dropping rpms

ed r still here!