250 SHO break in making oil

[hillbill]

OK the history

I bought a 2010 FX 21 with 48 hours on the clock, the TSB had never been done on the engine, before buying and knowing this engine was in the TSB range I had a Yamaha mechanic contact corporate and see if they would cover the block, they did and it was replaced in Janurary, all is well.

I ran the engine the first two hours per mechanics instructions and dropped the oil and filter and put in fresh, I know, probably not necessary but it's done. I put in 6 1/2 quarts and it was half way between the marks on the stick, leaving room in case it made oil which these engines are famous for. Well it has, at almost 8 hours the level is at the full mark, so about a half quart of diluted fuel is mixed with the oil.

Advise:
do I just drain it down a little and proceed or start over fresh? run it like it is? I don't like the idea of diluted oil in a new engine.
the last few hours have been just normal running while fishing.

Take it out and run the crap out of it?
need advise from those who have been there.

[Hchamberlin1]

Mine made oil for 6 hours then changed it. If your still not over full it’s fine. I’d run it hard 4-5 hours varying throttle up to 6000 rpm then change it again and likely then it’ll be good till your 20 hour oil change. I worried to death about mine making oil but since I just started running it hard it hasn’t made anything up to my first service.

[fishfanatictcg]

Going through same thing. Contacted Yamaha rep who advised up to 10 percent fuel in oil should not be a problem. When or if you get close to that number change the oil. Make as long of high rpms runs as possilbe, let it cool off and repeat. At some point the rings will seat.

[Yatesville Junkie]

Take it out on a river system and run it against the current as hard as she will run. Run it like you stole it for an hour or more.

[Delta Bass Fool]

If you want to be safe then drain the oil and put fresh oil in. I am thinking it’s better to be safe than sorry. I don’t know about the break in period on these new engines, I’ve never owned a new outboard engine but the mechanical aptitude in me says if you are going to run it hard to promote the rings to seat you might be better off with fresh oil that is not thinned down so you keep the optimum lubrication and oil filming of the bearings etc.

[Hollada]

If it keeps making oil after you run it hard like recommended above, have a mechanic confirm the thermostats are opening and closing correctly.

[hillbill]

Thanks for all the replies guys!

[cggarner]

Mine made oil for 6 hours then changed it. If your still not over full it’s fine. I’d run it hard 4-5 hours varying throttle up to 6000 rpm then change it again and likely then it’ll be good till your 20 hour oil change. I worried to death about mine making oil but since I just started running it hard it hasn’t made anything up to my first service.

The 10 % is much higher than I have seen in my oil sampling and my engine has made oil up through 60 hours. My first 3 samples were 4.5%, 3.5%. and 3.0% gas in oil. The oil lab is saying anything over 3% gas in oil is above normal. I am not disputing 10% and that may very well be the limit. One consideration in oil level is the amount of oil trapped in the engine after it is drained. So with the addition of 6.5 quarts, you shouldn’t be over filled. No one mentioned using conventional not synthetic oil during the break in period. Make sure you are using the conventional not the Yamaha synthetic oil. Since my engine made oil, I am continuing to use conventional oil until I am sure it isn’t making oil. Another issue is the way I run the engine. Lots of idling and starting and stopping. Drug it up to Guntersville for the good old Guntersville long rides and it seemed to really help. Those long runs WOT and you think you will never get there.

[Wackyjig]

Does the oil on the stick smell like gas? Reason I ask is SHO's tend to get overfilled on oil because they trap about half quart when drained. Fill is with 7 like it says and it'll be overfilled.
I fill mine with 6 and half when i change oil then after running the level comes up from midway to the top dot and stays.

If it does smell like gas it's time to beat on it a little and it'll stop. Make sure you're turning 6k or more at wot. If not take some gear out until you can. Run it for 10-15 min at wot and full trim, shut it down and fish then run it the same at wot again. After 4 or 5 long wot runs and heat cycles it should be good to go. The more hours you put on it with the rings not seated the harder it will be to do later.

[kry29]

I bet some of that was just left over oil from the oil change. Probably do need to do some long runs though to get the temp up and keep it up

[hillbill]

I am running conventional oil
likely will even after break in.

I take it many pump it out, I dropped the plug and tilted the engine up and turned the engine full right, seemed to get it all

I just changed it out, makes me feel better about it if nothing else, went back with 6 1/2, half way up the stick.
next time out I will make some long runs at WOT, love this boat and engine but the break in process sucks.

[kry29]

The conventional oil is good. I switched to synthetic after my 100hr change and once summer hit it made more oil. I switched back to conventional and so far it's good but I'm still keeping an eye on it

[jmartin56]

My experience and advise from my mechanic is that ALL 4 strokes will make some oil. Just the nature of the beast when you don't run WOT a lot and have short runs or lots of idling. Here on KY lake i get a lot of idle time. The fuel doesn't completely burn off and works its way into the oil when the motor doesn't get hot enough. My mechanic also told me not to worry about it as the oils are designed to run with 10%+- gas mixed in the oil. Now much more than that, and I'd be a little worried and start to change out. This was on my old Verado that I ran into these problems, but I'm in the middle of a swap out to a new SHO.

That's my two cents anyway!

[Nickl]

My experience and advise from my mechanic is that ALL 4 strokes will make some oil. Just the nature of the beast when you don't run WOT a lot and have short runs or lots of idling. Here on KY lake i get a lot of idle time. The fuel doesn't completely burn off and works its way into the oil when the motor doesn't get hot enough. My mechanic also told me not to worry about it as the oils are designed to run with 10%+- gas mixed in the oil. Now much more than that, and I'd be a little worried and start to change out. This was on my old Verado that I ran into these problems, but I'm in the middle of a swap out to a new SHO.

That's my two cents anyway!

It’s a joke that they get gas in the oil .If your new car did that if you didn’t drive 120 mph what would you do.You should be able to run any speed with out gas getting in the oil.I sure like the old motors better.I sold a evinrude 150 .14 year old still running great.

[kry29]

It’s a joke that they get gas in the oil .If your new car did that if you didn’t drive 120 mph what would you do.You should be able to run any speed with out gas getting in the oil.I sure like the old motors better.I sold a evinrude 150 .14 year old still running great.

Cars are temp controlled at around 210. Boat motors around 140. That's the difference

[Wackyjig]

It’s a joke that they get gas in the oil .If your new car did that if you didn’t drive 120 mph what would you do.You should be able to run any speed with out gas getting in the oil.I sure like the old motors better.I sold a evinrude 150 .14 year old still running great.

You can run any speed, after it's broken in. Mine made oil until 7-8 hours and hasn't since, even with synthetic. The only time I run hard is during my 1 tournament a month, the rest of the time i'm between 4000-4500 cruising and I idle a ton scanning offshore through the year.
kry29 is also right about temperature in cars vs boats. The trick to seating rings is getting the cylinders hot. I've got engine temp through nmea and mine will not break 140 until I get above 5500 rpm and stay there for a while. I made a 28 mile run back to weigh in saturday and I held it pinned the whole way back running between 6050 and 6100 rpm and 145 was as warm as it got.
Car engines are also broken in by computer before they make it to the lot as well

[ChooChooSnakeMan]

My experience and advise from my mechanic is that ALL 4 strokes will make some oil. Just the nature of the beast when you don't run WOT a lot and have short runs or lots of idling. Here on KY lake i get a lot of idle time. The fuel doesn't completely burn off and works its way into the oil when the motor doesn't get hot enough. My mechanic also told me not to worry about it as the oils are designed to run with 10%+- gas mixed in the oil. Now much more than that, and I'd be a little worried and start to change out. This was on my old Verado that I ran into these problems, but I'm in the middle of a swap out to a new SHO.

That's my two cents anyway!

I'm watching this thread since I have a 250 sho and as an engineer I find the subject interesting. As stated I think the whole problem in our engines is that the oil doesn't get hot enough to keep blow by fuel burned off. 140 to 145 degrees is not close to what other closed cooling system 4 stroke engines run at or even air cooled engines. I'm following information about the new Merc 4 strokes and at least from what I've been able to read Mercury seems to be trying to prevent fuel accumulation in the oil sump of their new engines by somehow allowing the oil temperatures to run much higher than our sho motors. I've read temps of over 240 degrees! I'm hiding and watching as they may have set it too high. Oil, at least conventional oil has a tendency to start breaking down around 260 to 280 degrees, at least what I've read. I understand that the oil that comes off the cylinder walls can be 50 degrees or so higher than the sump temperature so it seems to me that Merc may be setting up the opposite problem we Yamaha sho owners have. Our engines don't get the oil hot enough to "burn off" any fuel that blows by while their engines may actually be allowed to get so hot that while burning off the fuel they may be taking a chance of actually breaking down the protective properties of the oil. Anyway I wish our engines could be modified to allow the oil to get to around 190 degrees and stabilize there. That would be perfect and I don't think we would be having this problem.