2019 Mercury 300r Problems/surging

[dclay20]

Serial:1E080946

Surging at 4000 rpms........

Boat gets up on plane fine and will rev fine coming out of the hole. RPMS will climb to almost 5000rpms and then start shutting its self down to 4000 rpms. Seems like its getting put into guardian mode. The motor will repeat the process over and over. Motor ran perfect on the previous boat.

[EuropeanAM]

Any warning horn or Smartcraft Warnings being displayed?

What boat is it on now (and how is the fuel supply to the engine configured)?

[dclay20]

There is no warning horn.

3/8" fuel line

Havoc 2172 elite

[EuropeanAM]

Thanks.

Make sure the fitting at the cowling is actually 3/8" ID (there's a 5/16" fitting as well, which would be a bit restrictive).

Verify that there is only ONE (1) fuel filter between the tank and the FSM. This means that if there is a filter in the boat- there must be a BYPASS installed at the back of the engine where the original in-cowling filter was.

Verify that filters in the fuel rails are clean (recommend a dealer do this- LONG cone-shaped final filters for the rails/injectors).

If all are as they should be, it will be necessary to get a vacuum gauge "teed" into the line to read what the fuel restriction value is at ALL engine RPM's (idle to WOT, on the water).

[dclay20]

Previously it had a fault code "esc4". I cant find anything on what that is.

[EuropeanAM]

Ignition Coil or circuit problem. There's a numeric code attached to that that gives more information on what the problem might be.... be careful because it may not be "Cylinder 4" that the problem is on.