250 SHO break in making oil

[hillbill]

Advice
Ok so I purchased a 2010 FX21 with 48 Hrs on the clock, before doing so and suspecting the TSB had never been done I got the dealer mechanic to contact corporate to make sure they would cover the short block, they replaced it and all is well except for making oil which I see is typical for these engines. I drained oil and replaced filter @ after 2 hrs, I know, likely not needed but it's done. I refilled with 6 1/2 quarts leaving some room on the stick, ( half way between the marks) it's now at almost the full level after 5 hours.

Question is do I keep running it like it is? drain some? drain and start over? it bothers me that it now likely has a half quart of diluted fuel in the oil.
I did the first 2 hours by the book, didn't run it past 4000 the third hour and just normal stuff since.
Drain, refill and run the crap out of it or just keep at it til hour 10 and then run the crap out of it?

[PlanoKeith]

I have a 2018 250 Sho. The first two hours is when they make the most oil. My oil level was 3/4 inch over the top mark. I changed mine at 6 hours with new filter. I took it to the lake and ran it for 4 to 5 hours at 5500 plus rpms with no stopping. ( i have a bay boat so can't go like you bass guys ) . It quit making oil. I think you should smell the oil and if it doesn't have a strong smell of fuel run it hard like i did and then check the oil. I have checked my oil several times and it stays the same .1/4 inch under the top mark. Good luck :)

[Hchamberlin1]

Since your past your 2 I would run it for 3 hours or so varying rpms up to 6000 and re check. Then I’d run the next 5 as hard as the lake allows. Mine rose 1.5 inches up to 5 hours or so and I changed it. Started running it at 6000 sustained and it’s been fine

[bgibson]

I followed the new Mercury 4 stroke break-in procedure on my 250 SHO new powerhead. 10 hours and oil has not raised from half way up the dipstick. I broke in the original powerhead the way Yamaha explains it in the book and I made oil like crazy! Just teling you my personal experience. I think these Yamaha's need to be opened up early in the break in procedure or oil making is going to happen.

[CJ1]

I followed the new Mercury 4 stroke break-in procedure on my 250 SHO new powerhead. 10 hours and oil has not raised from half way up the dipstick. I broke in the original powerhead the way Yamaha explains it in the book and I made oil like crazy! Just teling you my personal experience. I think these Yamaha's need to be opened up early in the break in procedure or oil making is going to happen.

Could not agree more. Yamahas break in is the worst thing you can do to a fresh engine. Idle it for a full hour?? Seriously! Cj

[smallykiller]

Since your past your 2 I would run it for 3 hours or so varying rpms up to 6000 and re check. Then I’d run the next 5 as hard as the lake allows. Mine rose 1.5 inches up to 5 hours or so and I changed it. Started running it at 6000 sustained and it’s been fine

I did the same, no oil issues.

[1GThompson]

A big contributor to making oil is being over-propped. You need to make sure you sho will turn at least 5800 rpm wot. If it can’t it will make oil.

[hillbill]

Update:
After getting tired of this thing making oil and changing it again about the 10 hour mark due to dilution I took it out 3 trips back and ran it at 6000 about 15 miles one direction, set it down ,let it cool about 10 minutes and ran it the 15 miles back, since it has made no more oil. I think finally the rings are seated.

the mechanic wanted me to keep with the program but I decided to take the advice of guys that had been there and I'm glad i did, Thanks to everyone that commented.

[lamoon78]

They really never will stop completely from what I understand you start idiling a lot it will start again. It’s something every 4 stroke engine does even the new Mercs do it. That’s what I been told by a reputable mechanic. You just have to keep an eye on it all the time. You just have to constantly run the hell out of it. I seated mine then it started again after a lot of graphing.

[dawg08]

I’m about to purchase the 250 SHO and saw this thread a few days ago. I called them about it and they told me they had a Yamaha engineer come to there place to discuss the same exact issue. The engineer gave them a completely different break in sheet than the original manuals break in. Basically they said with the original break in the plasma cylinders were not staying hot long enough to seat the rings correctly. The plasma is designed to run cooler once the motor is completely broke in. They now want you to run it like you stole it 20-30 minutes straight. We didn’t get into how many times or what not, just some basics of it. I’ll get that info when I take it in for the install. This is coming from my dealer so my advice would be to call yours and discuss this with them.

[skennedy]

Best thing is to not break them in with synthetic oil . I ran mine with just straight Yamaha oil for the first 100hrs it stopped making oil after the 10 hr Mark . I have been running synthetic oil for the past 60 hrs . I do a lot of idling to get way back in the creeks on the Ohio River and ledge fish Kentucky lake a lot . Oil level never moves .