Mercury EFI Saltwater Series 200HP - Wont rev past 2400

[mjhenry04]

Hey Guys

S/N 0T514288

Problem happens when I hit between 2000 and 2600 RPM. It fluctuates at where it begins from test to test. Boat refuses to get on plane. Giving more throttles produces nothing but a slow rhythmic shutter, but it wont stall unless you really try to punch it.

Checked Compression, good across the board- on trailer and under load.
Checked Fuel pressure- Steady 36psi on trailer and under load all the way through issue.
Checked Spark- No issues on all six wires on trailer and under load all the way through issue.

Bulb is tight. Back-flow prevention valve replaced this summer, no issue. All filters and water separator clean.

Spark plugs replaced this summer.

Tried the trick of disconnecting the temperature sensor, no change.

 

[aussieflash]

Re: Mercury EFI Saltwater Series 200HP - Wont rev past 2400

Test Stator first with resistance/ohms test.Trigger and coils can be tested in same way.Disconnect battery first.

 

[mjhenry04]

Re: Mercury EFI Saltwater Series 200HP - Wont rev past 2400

Test Stator first with resistance/ohms test.Trigger and coils can be tested in same way.Disconnect battery first.

Well looking at the diagrams here: http://www.**********/parts/search/MercuryMarine/0T514288/6996/parts.html

I don't see a stator as part of the set up. http://www.**********/parts/search/MercuryMarine/0T514288/6996/50/FLYWHEEL-ALTERNATOR/parts.html

 

[mjhenry04]

Re: Mercury EFI Saltwater Series 200HP - Wont rev past 2400

Test Stator first with resistance/ohms test.Trigger and coils can be tested in same way.Disconnect battery first.

This motor does not have a stator.

 

[Faztbullet]

Re: Mercury EFI Saltwater Series 200HP - Wont rev past 2400

Sounds like the puter put it in guardian mode....

 

[mjhenry04]

Re: Mercury EFI Saltwater Series 200HP - Wont rev past 2400

Sounds like the puter put it in guardian mode....

Would it still tremble in guardian mode? The throttle still works and tries to keep going

 

[Fun Times]

Re: Mercury EFI Saltwater Series 200HP - Wont rev past 2400

You're to low on fuel pressure, you need it to be between 41 psi – 45 psi (283 kPa – 310 kPa) not 36 psi.
IMPORTANT: When checking fuel pressure while engine is running, fuel pressure
may fluctuate. Fuel pressure fluctuation [i.e. 41 to 45 psi (283 to 310 kPa)] is common,
as the regulated pressure is a differential between fuel rail and manifold vacuum.

This link will get you through all the fuel testing procedures,
http://www.120.b.hostable.me/mercury/225EFI-250EFI/3b.pdf

But the mercury service manual you need for this engine is merc part number 90-883728 - 150/175/200 EFI.

Bear in mind, If it goes into guardian mode I believe you would normally get a warning horn.

Good luck.

 

[Faztbullet]

Re: Mercury EFI Saltwater Series 200HP - Wont rev past 2400

If it goes into guardian mode I believe you would normally get a warning horn.

If horn is operating,,,,

Would it still tremble in guardian mode?

Yes as ECM retards timing ..

 

[mjhenry04]

Re: Mercury EFI Saltwater Series 200HP - Wont rev past 2400

You're to low on fuel pressure, you need it to be between 41 psi ? 45 psi (283 kPa ? 310 kPa) not 36 psi.
IMPORTANT: When checking fuel pressure while engine is running, fuel pressure
may fluctuate. Fuel pressure fluctuation [i.e. 41 to 45 psi (283 to 310 kPa)] is common,
as the regulated pressure is a differential between fuel rail and manifold vacuum.

This link will get you through all the fuel testing procedures,
http://www.120.b.hostable.me/mercury/225EFI-250EFI/3b.pdf

But the mercury service manual you need for this engine is merc part number 90-883728 - 150/175/200 EFI.

Bear in mind, If it goes into guardian mode I believe you would normally get a warning horn.

Good luck.

I meant to type 46 but firefox wont let me edit after the fact.