Do All 4 Strokes Make Oil.......

[Texasmark]

Or does it depend on how you use them and the climate?

Anybody remember the Homelite of the '60's? Did they "make oil too"?

Thanks,

Mark

 

[JRJ]

Re: Do All 4 Strokes Make Oil.......

Mine does not make oil. When I use it, I run it enough to get it up to operating temperature.

I cut a lot of wood with Homelites, but never saw one on a boat.

 

[zzzzz]

Re: Do All 4 Strokes Make Oil.......

it depends on both climate and type of usage...if you do a search you'll find alot of posts about this

 

[TOHATSU GURU]

Re: Do All 4 Strokes Make Oil.......

The broad answer is yes. Due to their raw water cooling system they tend to run cold and fuel slowly dilutes into the oil at low operating tempatures. In warm climates, with operation above an idle, it isn't an issue. In colder water, if you do a lot of trolling, it's a minor issue. Run the lowest "weight" oil that your manufactuer recommends if you can as that seems to help. Synth oils shouild be shied away from as well if fuel dilution is an issue for you.

 

[JB]

Re: Do All 4 Strokes Make Oil.......

No. Not all 4 stroke outboards make oil. My DF70 Suzi didn't, nor did my 97 Johnny 9.9 4 stroke. I have theories why, but no facts.

I don't recall the Homelite/Fisher Pierce Bearcats making oil either.

 

[TOHATSU GURU]

Re: Do All 4 Strokes Make Oil.......

And the broad answer is still yes.

 

[Rancherlee]

Re: Do All 4 Strokes Make Oil.......

I'm not sure if all 4 strokes have a crankcase ventiation system which helps alot in keeping the moisture out and keeping it from "making oil". I no my Johnzuki hasn't made oil yet and I'm going to send my next oil change in for an oil test to see what kind of bad stuff is in the oil (free for me where I work). Also our buoy rig which is a 28' pontoon with a 50hp 4stroke merc on the back hasn't made any oil yet and it mainly runs at near freezing temperatures with about 80% trolling time, only time it gets run hard is getting to the first buoy to pull and getting back to the landing with a full load.

 

[Texasmark]

Re: Do All 4 Strokes Make Oil.......

Rancherlee, that is a very interesting comment. I'm a mechanism guy; you know stuff doesn't happen, it's caused.......by what?

So here you are doing what should make oil and you don't? I'd bet a lot of folks who have 4 strokes in cold climates, that troll a lot, would like to know the answer to that one.

Mark

 

[Rancherlee]

Re: Do All 4 Strokes Make Oil.......

From what I've been seeing it seems that bigger 4 stroke seem to be getting alot of complaints on making oil. I see the Yamaha F115 talked about alot with this issue and few other bigger 4 strokes that see alot of trolling time on bigger boats. Our 50hp is strictly used in the fall just before the ice starts to form on the lakes to pull buoys off of 3 large lakes, sometime its around 15*f in the mornings and only gets to 40*f during the day when we do this. At the end of the day we run it about 1/2 throttle for 15-20 minutes to get back to the boat landing and thats about it, any more and the engine cavitates since we have it mounted so high to keep it off the reefs we are marking and it would get swamped when we have 3000# worth of buoys and weights aboard if it was mounted where it normally would be on a pontoon.

 

[TOHATSU GURU]

Re: Do All 4 Strokes Make Oil.......

I should probably add at this point that "making oil" is often not seen in many applications(even though it is occurring) and by many people. Some engines loose oil for various reason at a rate equal to or greater than the dilution rate. Some people change their oil often enough that they can't see an increase. Some people have engines that run warm enough by design, are in warm enough water and run at enough RPM that the dilution is minimal to the point of being unobservable by measurement. I would WAG though that their oil, if run for 50 hours or more, probably would have a measuable amount of fuel in it. We probably shouldn't even use the term "making oil" since it only describes the worse cases. How about "dilution effect" or does anyone have a better term?

 

[Texasmark]

Re: Do All 4 Strokes Make Oil.......

I hear you. Making oil is a misnomer, but that's what gets your attention. All of a sudden the reading on the dipstick is higher than it was and it is measuring oil and you didn't put any more in it.

So you said fuel, I was thinking the problem was condensation. Fuel dilution is a problem to all engines, but at least it is petroleum based, even though not a lube. Water on the other hand is "rust".

Mark

 

[mobyjaws]

Re: Do All 4 Strokes Make Oil.......

Forget the oil. How do you get one to make gas? MJ

 

[Skinnywater]

Re: Do All 4 Strokes Make Oil.......

Although not a cold climate my BF50 would idle for hours in 55deg. water and not make oil. I'm not sure how it would be proper and still pass EPA testing.
If they run that rich they would be extremely hard to start hot, their fuel consumption would be greater than a 2stroke, they would "lope" at idle and stink of unburned fuel.

I thought that the excess fuel might be from a motor that has been tilted regularly and it might be from overflow from the carb bowls. Or a genuine failure, float levels to high or a leaking fuel pump diaphram.

"Making oil" in a fuel injected 4stroke, I'm not sure if any "condition" would make me accept that it is "normal".

 

[Texasmark]

Re: Do All 4 Strokes Make Oil.......

Appreciate the comments folks.

Mobyjaws, if you can figure that one out you'll be a rich man. Grin.

Mark