Mercury F100 PT 2006

by Neville
(South Africa)

Hi I was asked, by a friend to assist with changing the impeller/water pump on his motor. Done that and its pumping water as it should.
Took the boat for a test run and here is what happened. Started up and idled with a bit of twitch every now and then,
When you throttle up, just as it get onto plane, it feels like it's running out of fuel, or poor fuel pressure. I was told that the " Guardian system " kicks in and it does not allow more than 300 RPM.
Took it to the local agent and had a diagnostic test done.
Results:
Hight oil input pressure
Gear position switch

The oil was overfull and they advised that it was it was the incorrect propeller causing it to over fuel.

I changed the oil and the filter, un plugged the gear position switch and took it for a test run.
Same issue when you just get on to plane and after idling at the launch, it shuts down and does not want to start again.
The cylinder head was cool, but the crank case was hot.

I checked the thermostat and it felt a bit stuck in the housing. I removed it and tested it in hot water.
It pushed the pin forward, but did not go back to the shut position again.

Tried to start it on the hose , but no luck.

Changed the spark plugs and it fired up, idled smooth and revved up clean. Shut it of and tried starting it again. Not starting.

Unplugged the fuel pump and it fired up again, but the water was not on , thus I switched it off quickly.

Checked the fuel pump assemble and it was empty. I can hear the pressure pump working I turn the ignition on, but cant confirm the lift/supply pump working.
Tested the lift/supply pump on the bench and it fine.

Now this motor still does not want to start.

I even fitted a primer bulb in the fuel line to try and prime the flout bowl.

Still not starting ..

I need Help please.