How to break-in a fresh motor?

[pyro]

I searched on the topic all the way back through 2003 with very little success. What's the "by-the-book" method for breaking in a freshly re-built Nic motor such as my Bridgeport? I want to do this right and make it last. I've got a couple gallons of Merc Premium Plus oil waiting to be mixed. I need to know specifics: What RPM's for how long, hose vs. neutral vs. in-gear running. Chugging along slow, or barely on plane, stuff like that.

Thanks in advance...

[Wolverine]

Lots of opinions on this one I'm sure. I usually run mine on the hose for 15+ minutes to flush it out, then back it into the launch and run it on the trailer for another 15+ minutes in gear to give it a slight load and to get some heat into the motor..........raising the RPM's to around 2000 momentarily or you can just launch the boat and do the same thing while enjoying the scenery and your favorite beverage . Let it cool down. Then go out and run it with some common sense......don't stab the throttle or make any full throttle passes....... for one tank of break-in mix. After that.......run it as normal.

[SUPAJAY]

Ive always been told to run it the way it will be ran for its life.

[us1]

I basically agree with Rob. I slowly increase the RPM hour after hour until 10 hours is up. The biggest trick I know for a good break-in is to let the motor cool over night after each 2-hour run. This lets the pistons and cylinders cool totaly and change shape without scoring.

[1BadAction]

During break in, mix oil and gasoline at a 40:1 Ratio (I would mix 25:1 with that motor, since it doesnt have a "break in mode")

Always vary throttle setting during break-in.

First 2 hours of operation

• avoid wide open throttle
• avoid full throttle acceleration
• avoid remaining at a constant speed for more than 2 minutes
• avoid sustained idle or running below 1500 rpm

1st hour - do not exceed 1/2 throttle or 3500 RPM
2nd hour - do not exceed 4500 RPM
Hours 3-10 Do not operate at wide open throttle for more than 2 minutes

[Ted Stryker]

These are the common recommendations for a new engine... I've wondered if the same tactics apply to a rebuilt engine... I know that the rings and bores will require the same treatment as a new one, but what about the work hardeneing of the journal and bearing surfaces.. A rebuilt engine using the same rotating assembly has a rotating parts that are essentially already broken in... So what does it take just to break-in the rings and bores...

[us1]

10 hours on a motor you want to last a long time and have good leak down.

[Juggernaut]

there is a lot of controversy on this topic. some people belive you should double oil mixture and do basically what BadAction posted. others belive after letting it warm up, whomp the **** out of it. allegedly it helps seat the rings. thats about all i know so im going to leave it at that.

[Reaction19]

I Always Let The Moror Come Up To Operating Temp The First Time While I Look It Over And Make Sure Everything Is 100% And Their Is No Leaks And Check Timing And Fuel Press. Then Let It Cool Off And. Run It Easy For A Little While So It Build A Little Carbon Then I Hold It Wide Open And Cruise Back And Forth A Couple Of Times To Build Heat And Cool Off It Helps Seat The Rings Fast. Then After A Couple Of Times I Let Her Eat. I Never Double The Oil Up I Feel It Is Unneccessary And Doesnt Let The Rings Seat. I Do How Ever Jet Just On The Rich Side To Be Safe And Then Bring It Back Down Till I Get Her Right On The Money. I've Done This Numerous Times And Had Great Success With No Failures. But This Is How I Do It Everyone Should Do What They Are Comfortable With.

[rocket1]

Her is what my 2005 outboard operation manual says, the little black book you get when you buy new. With efi you do not need to pre mix gas. First hour, Allow engine to warm up 30-60 secs. Avoid continuous operation at idle speed for more than ten mins. Run the engine majority of the time between 3000 and 4500 rpm. Vary engine speed, change speed every 2 mins. Avoid trimming outboard out beyond vert. position. Short burst of full throttle for periods up to ten secs. are acceptable. Next three hour change speed every ten minutes. Hope that helps?? Greg

[pyro]

Keep in mind, I'm specifically asking about COATED motors (Nicom/Nicasil, etc)

John, give me some more details. Tell me more about those ten hours. I'm not even sure I can plane off without exceeding 4000 rpm, I can't recall.

[us1]

Keep in mind, I'm specifically asking about COATED motors (Nicom/Nicasil, etc)

I was just going to point that out. If you email me I will email you detailed instructions on how I break-in a high performance lake motor. The first 10 hours is to break-in the pistons and cylinders. The rings will seat after 10 hours when you open it up and builds heat. [email protected]

[T-REX]

Cold, HOT, cold, HOT.....I'll give ya what haz been 100% on time for me so far...Now I built a stand, specifically for break'in in a mota(which also works good for runn'in a stored power head)...If the engine haz new forged pistons, I fire it on 40:1 mercury premium blend oil, and regular gas...1200rpm for 30 min @ 160*...Kill and let water circulate thru it for 1 hour...Fire, for anuther 30 min, and repeat cooldown.....6 thirty min runs, and cooldowns, then 3 one hour runs @ 1500rpm, with temps at 180*, and 2 hour cooldowns...Once that is complete, it's put on the boat, and hits the water with 20gallons of 20:1 oil/fuel mix, keep'in rpm under 5K, but up and down, not holding in one rpm range....after that 20 gallons iz gone, it will take any thang U kan dish out(From a break'in stand piont)....

Az juss fer new rings, I run the mota on tha stand for 3 ,30minute runs and cooldowns, and a 1 hour run, more for my satisfaction than anythang, because the rings will be break'in in for a while to kum...3 hours on the stand without a load will bring forth any problems, if I have screwed sumpth'in up while assembling tha mota, so tha owner ov tha powerhead knows it's runn'in, and in work'in order when he leeves tha shop, and so do I....

Juss my 2 cents on tha matter...Rite or wrong, it haz worked for me, and haz cut the amount ov stuck wiesco's damm neeer ta zero!!!

[twinrigskier]

break it in like your gonna use/race it!

[Hydrasports205]

I got REX to run mine on the stand and then followed his procedure - of course mine's a steel bore motor. I've got about 15 hrs on it and it's runnin like a scolded dog.