cloudmaster_321

Well, I did put an oil thermostat on the boat last season after the rebuild. My oil temp guage wasn't working but using an infared gun on the oil filter today showed 190ish. It's a 210 oil thermostat. I'm more worried about some kind of a water leak. I don't know if i would have room for the external filters. I have about 2.5 inches on one side, half that on the other. Stock 502 mpi.

The dipstick itself wasn't being pushed out of the tube, the oil was coming up and out of the hollow handle of the dipstick itself. What other dipstick should i get?

cloudmaster_321

Ya really think oil should be going that far anyways, seems if it's doing that, crankcase is being pressurized. Also, if those breather lines are getting that amount of condensation in them, how am i supposed to keep it from plugging up the lines? What else can i use on the stock 502 mpi for breathers. I did find these (Moroso 68741) breathers. But don't know if i will have room for them. If only one side is vented, is that good enough?

cloudmaster_321

Well i talked to the engine guy. He said the same thing as far as the oil temps go. I bought the oil thermostat from CP and i believe it was a 212 degree. Also, engine guy said my method of teeing the crankcase vent lines together and going to the intake is not adequate. He wants me to go to individial breathers as well. Not sure what to do about the thermostat.

cloudmaster_321

Well i went to the boat to reevaluate the breather system. I also went one step further and pulled the spark plugs to check them out. 3 out of 4 of the port side had water droplets on the plugs. One plug also had rust inside at the bottom going around the insulator. Another had a couple of tiny little rust spots going around the end by the electrode. The other plug on that side was perfectly dry and normal looking. I pulled the starboard side, and all the plugs looked normal, no water at all. So what's going on here. Am i still chasing a bad breathing system, or do i have other problems with a bad gasket or leaky manifold?

cloudmaster_321

Could be, but what's the culprite........

picklenjim

Like I stated earlier you need to open the oil drain plug to see if you have water in your oil.If it has set for a few days the water will go to the bottom and will come out first when you open the plug.Have you changed your breather setup from stock?Mercury has thousands of these engines out there and they certainly aren't having breather problems with them.If you have changed it you should return it to stock!

cloudmaster_321

I have not pulled the plug, but i could certainly do that. I will note that the oil level in the pan has not gone up , maybe down a tad from loosing it out the dipstick.

When i first bought this boat, it already had the eddie marine flame arrester with a k and n element in it. The flame arrestor has a hose barb on the back. The starboard valve cover had a fitting and hose that went to that hose barb. The port side breather had the mercruiser little baffle that just butted up to the flame arrester element. I changed this to the system i am currently running after i saw some oil or gunk coing out of the merc part and splattering around. I don't exactly recall the time line of when i had changed the breather system, and had this problem before the engine rebuild. I could put it back to the method stated when i bought the boat. But now i may have uncovered another problem with the plugs having condensation/water on them.

cloudmaster_321

I take it back. I remember how the breather system is now. I have the parts diagram to remind me. The starboard side has a elbow fitting in the valve cover, and a hose going to the port side where it plugs into the breather baffle. The breather baffle plugs into the port side. Then there is a short 2 inch piece of hose that butts up to the flame arrestor. There was a plug on the eddie hose barb. The original flame arrestor had a hose barb within close proximity to the breather baffle. With the eddie system, the hose would have to be about 6 inches or so.

cloudmaster_321

Don't know, could very well be an issue. The motor builder wants me to have all the plugs out, and turn the motor over with the starter to see if any of the cylinders kick out any water. Not exactly sure what he is looking for there, especially after telling him about the rusty plug.

picklenjim

Leaky head gasket or cracked head.