Engine Break-In
 

I have 496HOs - read the Mercruiser manual and it basically says to vary speed, avoid extensive idling and no WOT for the first 10 hours (3/4 max).

I have heard several say that it is good to run at WOT a few times to help seat the rings (small bursts - 30 seconds).

The obvious thing is to follow the manual however, will I hurt anything if I open her up for a short burst in the first few hours? Gonna be toigh not too :)

Watch the debris Shawn...the lake is up and dirty! I told Burl to listen out for you. :D

Well, I broke mine in by the book. But my buddy, who bought his boat at the same time, runs em like he stole em. From day one! And he has had no issue with his...except a blown drive. :D

The HO's are sweet motors for sure.

I only hope I will be so lucky with my 525's.

Shawn being the expert that I am.Do exactully the opposite that I tell you.RUN THE CHIT OUT OF IT.

...and put whipples on it!!!:eek: :D

But if you do have an issue, Merc could pull the engine statists from the computer and tell you..."Sorry, the warranty is void because you ran past 3/4 throttle"

Never heard that and I was a Merc. dealer.News to me.

I was speculating that they could do that, not that actually would do it. The computer tracks how much time it runs in every power band right up to WOT.

You know somebody is going to pull up next to you to see who is faster. Then what do you do? Hit it.

you are absolutely correct. all it takes is a rep with maybe a less than sane day and rules are rules.


not likely but possible.

use self control and protect your investment.

then after only 10 hrs its hammer time with no worries cause thats why you have a warranty.

Yup.....we had that happen with a pair of 2.5 OFFSHORE Mercury Racing outboards........they pulled out the rule book and ran the scan tool........did they honor the warranty......YES.... but it took some time and lots of dealer/customer pressure on Mercury to do it. It was close but they did warranty it. Follow the the manual and go an extra 2 or 3 hours in good faith if a problem does arise.....but those motors are basically issue free and turn key every time...GO HAVE SOME FUN :drink:

Correct me if I am wrong here. I know the computer tracks what rpm's the motor has run at. (I was amazed to find out just how much time I have spent in no wake zones.) But I don't think it tells you WHEN those rpms were logged.

I can understand 3/4 throttle for the first 2-3 hours......after that! Run it like you normally would if it had 100 hrs on it.

We just built brand new engines and sent them to the dyno....he ran them to near 6,000 rpms and they were just put together!!!

No time record is kept. My post would only be relevant if something happened during the break-in period.

I think you are pretty accurate here. This is unconfirmed, but a Mercury rep. at the LA Boat Show told me they can even tell when it was at WOT (I would presume relative to the number of engine hours, rather than the date and time).

Please ignore all the uninformed people who say to just run the engine at full throttle from minute one. They have an extremely small sample size to base their opinions on. I don't know of any "major" engine manufacturer who recommends this, nor do they durability test their own engines without a break-in period.

Michael

Then how about the issue of Dyno testing. All major engine builders dyno their engines immediately after assembly. Run them hard after minutes of break-in.

Kinda more of a question than a reply, but do the ECU's on the 496's (or any other high performance EFI Mercury) not have a break-in mode like the outboards do?

I know on a new 280, the ECU runs in a break-in mode until it has determined the motor has been "broken in"

I know the engine builders do this. I would like to hear more thoughts on this one as well.

I had a guy whos ecu tracked that 1/2 of the engines short life was pegged at the rev limiters. :eek: :eek:

There are a bunch of reasons why the small builders don't run break-in schedules.

They do not have dynos capable of running break-in schedules.

They do not have the manpower to run a dyno for hours and hours for just one engine.

They don't have enough dynos to run multiple engines on break-in schedules simultaneously.

They don't have customers who would would be willing to pay for hours and hours of break-in dyno time.

Their horsepower tests are run on the fly, and over in a matter of seconds, compared to the person who leaves the engine at full throttle across the lake (or other body of water).

Hope this helps.

Michael