Re: ELPTO-Trim motor help
In answer to the rest of your question concerning purging:
My Merc service manual which covers '94 up 3 cyl engines says that the fluid should be Merc PTT fluid or automotive ATF.
The procedure is basically one in which the reservoir is filled with fluid via the large hex/screw slot (plastic I think.....not looking at it right now) plug on the lower rear of the pump housing to the bottom of that hole.
Then the piston is moved up and down several times and fluid is added as required so that when finished fluid is at the bottom of the hole. If you have a clean hypodermic syringe, of like 20 cc, filling is a piece of cake.
They recommend putting the whole thing in a vise, filling and then via the blue and green trim wires, use a 12v source (battery works) and alternately drive the cylinder up and down several times. Top off the fluid to the bottom of the hole, replace the plug and you are ready to install back in the engine.
Mark