Fuel dilution Mercury 60

[sweezy722]

2011 Mercury 60hp 4 stroke with 25w-40 oil. Engine has 941 hours and oil has 23. 90% of the 23 hours was trolling for Walleye.
I tried taking it for longer runs to get the oil hot enough to get the gas out but it did not help.
When the level rose enough that I figured it was about 7% diluted I changed. By the viscosity it may be over 7%
The engine has always made oil. I always change when it reaches about 7% dilution.

4 Iron
0 Chromium
0 Led
0 Copper
0 Tin
3 Aluminum
0 Nickel
0 Silver
0 Titanium
0 Vanadium

5 Silicon
5 Sodium
0 Potassium

14 Magnesium
1920 Calcium
0 Barium
1056 Phosphorus
1292 Zinc
42 Molybdenum
4 Boron

no water
viscosity cSt 100C = 8.6
Base number 5.8

 

[bullwinkle]

Ouch-I think a good trolling motor or even a "kicker" outboard would help. I have a 4 HP Johnson that I'm going to mount on my 22.5 foot Mercruiser I/O for those times when it's just too shallow to run the 350 Mag.

 

[DoubleWasp]

Might be time to get those injectors tested, rebuilt, or replaced. We just eliminated FD problems in an 8.2 that had a bad injector washing the engine down in fuel. Make sure those spark plugs are in top shape as well.

 

[claluja]

Trav on here did a great job servicing my outboard injectors. Maybe give him a shout. And it reduced my fuel dilution when did injectors around 1000 hours.

 

[sweezy722]

I am just sharing my results. I am confident my injectors are ok. I am also confident my rings did not get seated when new. The engine has made oil like this since new. I have gone 60 hours and I have gone 16 hours.

In 941 hours I have put on 3 fuel pumps - 1 main computer - a thermostat - water temp sensor and several other things and none have made any difference in fuel dilution.

When I bought the engine new I ran it for 7 minutes and it shut down. The dealer had to completely rewire the engine. When I got it back it had several hours on it and they were idling. It was February in cold water and I have always felt like everything that happened was the worst possible scenario for the rings to get seated.

I got tired of chasing an unfixable problem long ago. The dealership was absolutely no help. So I change the oil when it gets to about 7% fuel and worry about other thing.

 

[DoubleWasp]

Ugh. Well at least you know how to get through it ok enough to live. Fantastic UOA other than the FD.

 

[DoubleWasp]

Originally Posted by bullwinkle
Ouch-I think a good trolling motor or even a "kicker" outboard would help. I have a 4 HP Johnson that I'm going to mount on my 22.5 foot Mercruiser I/O for those times when it's just too shallow to run the 350 Mag.


Not a bad idea. Power couplers hate trolling. Occasionally causes the failure of them over an extended period of time.