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Outboard makes oil, how much is “okay” and related questions

Greetings, I have a BF75 with the standard low temperature “makes-oil” problem if I run it at low RPMs (trolling) for longer periods of time without intermittent high speed runs to raise the engine temperature. Normally, the way I fish is not too problematic as I fish a large lake with large expanses between trolling structures. Last weekend, I fished with a friend and used different patterns, and the outboard made a significant amount of oil. I have three questions on which I’d highly value expert input:
  1. How much extra volume is sufficiently large that the extra volume is going to be problematic, and has my extra volume reached that threshold? Please see attached photo of my dipstick for estimate of how much extra oil volume my outboard has right now.
  2. If the volume is greater than that threshold (or should it get there in the future), is it okay to just drain some oil until it’s below the full-line and use as is? Or, is the effectiveness of the oil sufficiently decreased by the fuel that is the extra volume such that I need to do a full oil change.
  3. In an attempt to minimize the amount of oil “made” I do more “running around” (at least on some days) than I’d prefer, and would like to only do so as little as required. What is the temperature range to avoid (I get temperature data on my Lowrance via a NMEA network)?
Greatly appreciate any information and advice! <º)))><
 

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Oil pumped into the bearings keeps the metal bits from rubbing on each other.------Very important on a spinning assembly in waves , yes it is.------Best look into why the oil is thinning out !!
 
I'm not real keen on the idea the engine is "making" oil. Not saying it can't happen, just that it's a sign it needs attention right away if it's doing that (in my mind anyway). My guess is that if you get a good smell of that dipstick it's going smell like gas.

Is the motor running "just right", or are there issues with the way it's running?

There are 2 ways for gas to get into the motor. One is through a set of carbs that are flooding - which is why I was wondering how well it's running. The other way is through ruptured fuel pump diaphragms. The fuel pumps aren't rebuildable for some reason, leaving you with fact they'll need to be replaced if they are leaking.

If you have the right "tamper proof" bit, the pumps come apart easily with little in the way of potential surprises. What I would be interested in is the back side of the diaphragm closest to the engine. If you see gas there, the diaphragm is leaking, meaning you'll need at least one new pump..... -Al
 
I had a BF8 that would make oil on and off when I trolled. In every case the problem was a stuck thermostat. The engine never got warm enough to flash off the fuel from the oil.

If you had a hole in the fuel pump diaphragm, the amount of fuel accumulating in the oil would likely be greater than you are seeing.

Another thing that can contribute to fuel accumulating in the oil is operation at low speed at high altitude. I needed to re-jet my BF8 in order to troll at Lake Tahoe (6200 ft).

In any case, FC-W rated outboard oils are engineered accept up to 7% fuel dilution while still providing acceptable wear protection. See page 16:

https://www.nmma.org/assets/cabinet...d Certification Procedure Manual (5 19) 1.pdf
 
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