2007 50 E-tec approx 550 hours XD50

[gcmarshall]

One of the local fisherman is having some problems with his. It is his second service and they found water in the lower unit - turns out one of the seals seems like it was not installed correctly at the factory. But that's just an aside...

When he puts the boat in gear, it runs fine up to about 1800 rpms. Between 1800 and 2000 rpms it loses speed and the engine shakes very noticably. No alarms go off and no error codes are registered. (I attached my laptop and the only error code set on the engine is a low voltage one set a time back)

The mechanic serviced the engine and replaced the throttle position sensor.

Any ideas of what else to check, or suggest to the dealer to check? The rep from the dealer is supposed to come today to look at it.

[GhostComanche]

Give the experts model and serial numbers and I am sure that they can help out. .....................Roger

[gcmarshall]

don't have that info, but can get it if really needed. I doubt there is more than 1 model no. in that year for that engine anyhow.

[SEAHORSE]

The is a software calibration for the throttle sensor that should be checked. Using the laptop with the diagnostic software, a procedure is done that will tell the engine's computer (EMM) the travel of the throttle position sensor before the throttle plates start to open. It is a critical adjustment for engine smoothness.

Also the spring tension on the throttle plates should be checked to make sure the spring on the bottom of the shaft did not come loose or break.

[gcmarshall]

Thx - will give the dealer that info...

[gcmarshall]

Update

Somehow the EMM got corrupted and the engine would not start. A replacement EMM solved that problem.

It appears that a "shift switch" at the side of the engine was faulty and this caused the engines to have the problems it had when increasing throttle. Does anyone know what this is and why this would be the case? (there were no error codes on the engine using the diagnostic software)

[ezellmer]

Shift switch senses if the motor is in gear. If it thinks the motor is not in gear, it will not allow the rpms to exceed 1800 or so. The experts will know the exact deal, but one of our 90's had this issue last year with a badly misadjusted shift cable.