Oil making yamahas

hooktender68

hooktender68

Well-Known Member
I have an 08 F250, and it has made oil ever since I bought it. I have installed the hotter Suzuki thermostat, but it made no difference. I have been told to not burn marine fuel ??? mmmm Pretty hard to do that on the west coast all summer. Anyhow, I did give it a try, I had a half a day off guiding once a week and had a tidy tank in my truck and went to CR to fill. It worked out really well, the motor made no oil and I was actually able to make the 150hr service I like to do without feeling like my oil was shot and not doing its job. The BIG however, however was that it was expensive and highly inconvient, and now I am finding that when I do burn marine fuel the dye makes the oil rise faster than before!! WTF

Any body else having this happening to them? Looking for ideas or advice, OR a name brand motor that can actually handle "marine fuel"
 
Had the same issue with a pair of four cylinder Verado's. Apparently four stroke OB's which are raw water cooled and do not generate the heat in the oil necessary to burn off by-products, thus they make oil. (impurities) The cure, run them hard and generate some heat. The end of each day see's me run them at high RPM to generate heat, that heat burns off the excess and all is well. Oil Temp gauge on my Verado's run around 165 degrees when running normal (4200 rpm), a short run at close to max RPm (over 5000 rpm) sees this rise to about 210. Not sure if the Yamaha's the same as the Merc but same principal may apply. Hope this helps.

Hope the link works good description

http://www.veradoclub.com/smf/index.php?topic=2856.0
 
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Did you know that the cycling of an engine from cold to hot is what shortens an engines life. (expansion and contraction of metal and parts) I wouldn't want to run an engine hard (and hot) every trip to combat another problem. Seems like a band aid solution to me.
 
My motor does this when I burn marked gas, I was told that the dye is mixed in kerosene then added to the fuel, the kerosene doesn't burn like the gas and can get by the rings and make the oil level rise. I don't use marked fuel anymore, so far. F90
 
May sound dumb, but troll with it for a while...
I don't think its got anything to do with marine gas (usually 89 octane)
the biggest problem with 4 strokes is they don't stay hot enough
to burn off all residual gases...
condensation occurs causing oil levels to increase.
 
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After running on the way home your engines cool, you have a thermostat problem. Running a properly propped engine at the end of a run home has a great deal of benefit. Especially a four stroke, which by design passes by products past the rings and into the base oil. Four stroke outboards are unable to generate the heat necessary to burn of the ring by products. Case in point running at cruise engine temp 170; oil temp 150 running the RPM's up engine temp 170; oil temp 200 after a few minutes. Oil temp of 150 is insufficient to burn of the by products ( which combine with the oil and give higher level readings). Have a read of the link, theres a great deal of info that affects this on four stroke outboards. Are the Block thermostats working correctly; are the oil thermostats operating correctly; etc. etc. Ran the Verado's for a season and battled the making oil problem, have run the last two seasons following the above and had no problems since.
 
not overly keen about trolling with my big one especcially when its seated beside a9.9 but worth the try, just to see. Other than that the consensus seems to be to suck it. At 20+K a pop for a big main, it would sure be nice for the companies to be accountable.

Thanx for the opinions and advice so far
 
There is no way for any fuel that has passed by the rings into the crankcase to be burned off. By making the engine run hot you may burn off and prevent further fuel from entering the crankcase but the fuel that is already there has no where to go and doesn't get hot enough to burn off. The heat that could do that is on the plug side of the cylinder.
 
I have an 08 F150 and it began making oil two seasons ago. In the spring I had the hotter Suzuki thermostat put in and also ran a healthy dose of "Ring Free" through the first tank of gas for the season. I also ran some more through part way through the summer and my oil level seemed to hold all summer. Not sure if it was the thermostat or the Ring free that cured the problem. Since you alreadyy did the thermostat trick maybe try the Ring Free? My two cents........
 
I was thinking that it might be likely that the rings never seated themselves in properly right from break in. The only thing that doesn't hold up there is that the rising oil level stopped when he switched to unmarked fuels. That if correct would kill that theory.
 
profisher said:
There is no way for any fuel that has passed by the rings into the crankcase to be burned off. By making the engine run hot you may burn off and prevent further fuel from entering the crankcase but the fuel that is already there has no where to go and doesn't get hot enough to burn off. The heat that could do that is on the plug side of the cylinder.
Click to expand...

It doesn't have to burn it can flash off easier and be carried away by the evac system, 210° is nothing for a modern oil.
 
I had that in a fourstroke before. It would make oil and the motor oil turned red from the dye in the marine fuel I was using. I just changed the oil right on time and it was not an issue. Occasionaly I had to remove some oil but not too often.
 
It is just a pain in the butt. As the oil rises, and becomes colored, I do not see how an oil can retain its protective properties out to the recommended oil change intervals, that is why I opt to change it at 100hrs or a bit less. I had the same issue in my last engine, an 05 F225 that engine only made 850 hrs and is still a sore subject with me.

I will be selling this motor this off season while it still has warranty. Anyone who is running a V6 F300 Yami have any oil coloring/rising issues?
 
Isn't the usual oil change interval 100 hours - it is for my Suzies. Never had any oil making issues on them, but did on my Yami 9.9.
 
I had issues with my F90 making oil too. Changing the thermostat seemed to help some, but it was still rising.

Switching to non marine fuel seems to have pretty much eliminated the problem. Lugging jerry can's to the dock is no fun though - good thing the motor is extremely frugal.

I am still a bit freaked about the issue so the oil and filter get replaced every 50 hours - a bit of a pain during the summer months when I sometimes put on 50 hours in a week, but at least I have peace of mind.

My T8 does not seem to be making oil.
 
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Just a thought - for those of you concerned about what IS actually in your oil, get an oil analysis done. You will find not only about what is contaminating your oil, on top of your oils performance in protecting your engine (wear metals, additives remaining, etc.), but also about the condition of your outboard engine based on various wear metals present compared to averages. I have done this on my personal vehicles a few times as well as my brother has done it on a few of his and the information is invaluable. It can also tell you if you're wasting oil, or your oil change interval needs to be reduced, etc, etc. I've used blackstone labs south of the border. You contact them and they will send you some kits. When you do your oil change take a sample of it and mail it to them in the enclosed container. I usually have a PDF file emailed to me in around 5 days from the day I mailed it with an oil analysis report from them. The price last I did it was around $35. For a comparison you could always keep some of your virgin unused oil from your oil change and mail that to them as well in a seperate container. It'd cost more money (2 oil analysis) but it'd definately help you see what's going on in your engine with contaminants and things like that.
 
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