Hi there! I have a 2000 Mercury Sportjet M2 240hp motor in my Seadoo Boat which is causing me some headaches… First, I will put a new set of plugs in it and it will fire up and run very well all day, but as long as I don’t shut off the engine. Then it wont start up again. If I pull the plugs out and clean them with a solvent and put them back in, it fires up and runs until I shut it off. If I don’t clean the oil off of the 6 plugs, the engine refuses to start and I have to drain the vapor separator tank of fuel because there is too much oil in the fuel.  (depending on how many times I try to start the engine…) So far, I have replaced both oil line check valves, The oil pump, the temperature sensors, and the thermostats. Also the oil pump lever is properly adjusted to the factory specs and the compression pressure is at 135 PSI on all cylinders. I am using Quicksilver semi-synthetic oil. I don’t know what else I should be looking at!! I would appreciate any help… Thank you!!