Engine break-in

[Chowda]

Sorry if this topic has been beaten to death but I will be getting a boat with a df150 next month. I have researched the internet and there are two ideas out there about to break-in an engine.

One says to run it like you stole it in order to heat everything up and seat the rings, etc or you risk the engine "making oil".

The other idea is to follow the user's manual 10 hour procedure for initial break-in. I understand both thoughts but am leaning towards following the manual because I'm afraid of voiding the warranty if there is an issue and they check the computer and find out it wasn't broken in according to the manual.

What is your opinion on how it should be done? Thanks

[Moonlighter]

Follow the manual.

The only extra advice my dealer gave me was that during the run in process, where the manual says to run 1/2 throttle at 3000 rpm for a certain time, to not be afraid to go anywhere between 3000-4000rpm if running at 3000rpm would mean the engine was under load due to the boat not being comfortably on the plane.

In other words, dont worry so much about 3000rpm, just get the boat to a comfortable slow planing speed where the engine isnt under load like it would be if the boat was half planing. The ecu records engine time spent in each 1000rpm rev range, so an engine reving at 3100 rpm will not record anything different to one running 3800rpm.

Once run in, he also encourages at least a 5-10 minute burst of speed above 5000rpm each trip, conditions permitting.

Important to make sure the engine is propped so it can reach 6000rpm with a typical load on board.

Most of those “making oil” stories are not in fact due to rings not bedding. One of our experts on this forum rightly pointed out that the vast majority are due to incorrectly set or partly blocked VST floats resulting in excess fuel going thru the vapour tube into the crankcase. Easily fixed.

[Chowda]

Thanks Moonlighter.

[Greg Moore]

I would never second guess the people that designed the motor and follow one of the many 'parrots' on the Internet!! Years ago some older 2-strokes did well to be broken in the way you were likely to drive them (IE hard, not normally hard etc) but todays metallurgy and how incredibly dry a modern injected 4-strokes cylinders have to run, I'd stick with those that engineered the thing in the first place. Even modern car engines now have a breakin coating on the pistion rings to help control breaking for dummys. If it gets worn off from too many full throttle runs before cylinder walls get 'buffed' to the ring contour you can A, scuff the cylinders with the now bare chrome rings or B never get an even ring to cylinder wall. That doesn't even get into letting crank/rod bearings seat and shape to their journals

[2014DF25ARS]

I'll throw in one additional point, which I don't recall seeing mentioned in the User Manual for my DF25A engine, but which has been discussed on this forum: When my engine was new, I filled it with synthetic oil and proceeded to break in per the manual. But there seems to be a consensus opinion on this forum that you should NOT use synthetic oil during break in. The premise being that synthetic oil is "too slick" and won't allow the rings to seat properly. Anyone else here feel free to correct or clarify. In fact, I think I've been told that there are special "break in" oils available, though I have no experience with them.

[Greg Moore]

Pretty standard fare for any 4 stroke, car, boat or otherwise is to never break in on full synthetic. Cylinders are honed not polished. They're like an ultra fine file finish. This allows a small amount of material to be removed from the rings so they conform perfectly to the walls. Ideally you want the rings to seat very soon in the life of the motor. It's not just for the sake of good compression but also for the oil scrapers to reduce how much oil can get past them and be burned. Not sure you'd cause any specific damage running syn initially but you'd end up at the very least greatly prolonging the break in period. Normally the switch to synthetic would be the 2nd oil change. Break in on dyno oil, change at 20hr/50hr whatever is called for. Run dyno or semi syn for that change, then run best you can afford for all after that. It's presumed by that point the rings have accomplished their slight wear and conform to the cylinders as good as they ever will and you want to remove all wear after that point.

[ksny1000]

has anyone experienced lower max rpm after breakin. i had a df200apx put on the boat and after the 2 hours of running the tech brought it to full throttle and it hit 6100. now after it is past the break in period max i can get is 5600. and everything is the same - same weight on board same fuel same running location. now i am wondering if i have the correct proppeller

[Hoosmatroos]

Did you also trim the motor to get the optimum result?

[ksny1000]

yes i did. everything as we did at 2 hours
trimmed exactly the same

[jsocar1986]

Hey there everyone. I'm new to the forum, new to having new engines and new to the Suzuki brand as well.

Back in July of 2019 I purchased and installed twin DF200APXs on my boat. I have run the boat several times including following the manual's break-in procedure. With the several times I've run out and due to life (having first kid), work and other lame excuses haven't allowed me to run the engines up past the 20 hr mark.

Is there any issue with not reaching the 20hr mark sooner. Several people have told me that the engines are probably not fully broken in yet and that having not used it as often as I'd like would cause issues for me in the future. The engines have about 12 hrs and I turn them over monthly if I'm not able go out. Is there anything I should be concerned with? Thanks in advance!

[Chowda]

Hey there everyone. I'm new to the forum, new to having new engines and new to the Suzuki brand as well.

Back in July of 2019 I purchased and installed twin DF200APXs on my boat. I have run the boat several times including following the manual's break-in procedure. With the several times I've run out and due to life (having first kid), work and other lame excuses haven't allowed me to run the engines up past the 20 hr mark.

Is there any issue with not reaching the 20hr mark sooner. Several people have told me that the engines are probably not fully broken in yet and that having not used it as often as I'd like would cause issues for me in the future. The engines have about 12 hrs and I turn them over monthly if I'm not able go out. Is there anything I should be concerned with? Thanks in advance!

I have a 2018 and just went beyond the 20hr mark in June 2020. I intend to use the boat more but, like you, life got in the way for awhile. I suggest keeping the batteries on a good battery charger and put fuel treatment in a full tank of fuel. Any chance you get to take it out and run it I would.

Also, if you're going to start them monthly I'd at least get a large tub to set them in instead of running them on muffs and let them run for several minutes to get everything up to operating temp.