50 HP 4 stroke drips oil

[Bert1]

This is a 2001 Merc 4 stroke 50hp. It is not a fuel injected model. From day one I have alway's had a a bit of oil that seems to be coming from the bottom of the engine cowling, runs down the back of the foot and accumulates on the cavitation plate. There seems to only be a few drops each time I take the boat out (weekly)of the garage. I also noticed that I get a milkish fluid running down the seam directly at the back of the foot, from the water pump tel-tale to the cavitation plate, after I take the boat out of the water. No oil coming out the prop. The oil dip stick consistently shows oil about 3/4 of an inch above the high mark. During the first year it was on, but after the first oil change, it remains at that level. (Dealer cannot seem to figure that one out.) Should I be concerned??

 

[The Marine Doctor]

Re: 50 HP 4 stroke drips oil

If your engine is making oil...replace the T-stat, the engine is running too cool.<br /><br />TMD

 

[ebubeck]

Re: 50 HP 4 stroke drips oil

My 2001 90 HP merc four stroke was leaking in a similar manner. The oil pump had to be replaced.

 

[greasemonkeyozi]

Re: 50 HP 4 stroke drips oil

I may have misread, but drain your lower unit and inspect your lower unit gear oil for a milky color. Replace it with lower unit gear oil.

 

[Bert1]

Re: 50 HP 4 stroke drips oil

Thanks for taking the time the help, I will look into all of the above suggestions.

 

[The Marine Doctor]

Re: 50 HP 4 stroke drips oil

You might also check to see if the service bulletin was performed on your engine to replace the base gasket.<br /><br />TMD

 

[Bert1]

Re: 50 HP 4 stroke drips oil

Got engine winterized this morning. No signs of water in engine or lower unit oil. Dealer noted leak and indicated that no bulletin had been issued from Mercury on the 50 4 strokes, but they had seen some engine base gasket go. They confirmed that the engine oil war overfilled and that the problem may simply be overflow due to the overfill from a vent situated under the engine(??) They have noted the problem and we will monitor next season. (Warranty good until August 2004)

 

[DJ]

Re: 50 HP 4 stroke drips oil

Bert1,<br /><br />Make sure that issue is noted on both your copy of the Repair Order and theirs.<br /><br />They're proably honest, but you just want to make sure no one gets amnesia.

 

[The Marine Doctor]

Re: 50 HP 4 stroke drips oil

The T-stat should be changed yearly with these 4 stroke engines of the Yamaha breed.<br /><br />Mercury/Yamaha same powerhead.<br /><br />If your oil is too high its likely because of the engine running too cool and the themal valve staying open allow the engine to run rich and flood the carb. Excess fuel will wash past the rings into the crankcase. Making the oil level rise.<br /><br />TMD

 

[Bert1]

Re: 50 HP 4 stroke drips oil

Just to close the loop on this one, the dealer changed the thermostat this morning and we will monitor to see if oil level continues to rise. As for the dripping oil, could not pinpoint. Technician cleaned foot area (inside protective cowlings)as he thought it may have been the result of sloppy oil changes from past years that may have accumulated (oil from filter as filter is hard to change without making a mess). We will monitor. In passing, I would also like to note that when I contatcted Mercury through their Web Site, they got a technician to call me back within a few day's, from Vancouver of all places, to document the problem in order to provide the proper advice to the dealer. This was appreceated. Thanks ''Marine Doctor'' for your help as you where dead on with your advice.

 

[Bob_T]

Re: 50 HP 4 stroke drips oil

Since I am having a similar problem of gas in oil with a Yamaha T-50 four stroke, a couple of quick questions. How accessible is the thermostat and is it hard to change? Also, what temp t-stat should I be using?<br /><br />Thanks a bunch. Bob

 

[Bert1]

Re: 50 HP 4 stroke drips oil

Can help on the temp setting, but the t-stat is very easy to get at as it is on the top left hand side of the engine. It took only a few minutes for the tech to change it.