Breaking in a new merc outboard

boater1234

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Well i should be getting a brand new 20hp 4stroke merc any day now and was wondering if i need to break it in straight by the book?I thought i saw someone here say you can cut the time in half to like 5hrs instead of 10,is this true?Also i would think all you need to do is vary your rpms up and down and avoid full throttle and idleing for long amounts of time.It just seems 10hrs is way over kill.But if that is what it should be then so be it i may as well go by the book.I have heard from many people who have broken in outboards to just vary the speeds and you need to do it for like one full tank of gas which would be a 6 gallon tank in my case.I need some opinions on this please.Have most of you just varied the speed for like one tank and avoided wot or do most of you go straight by the book?

Also i have seen alot of people just break in their engine at home in a barrel of water,shouldn't you breakin a engine on a loaded boat?I have heard you should weigh the boat down as much as possible to make the motor work a little as that will break it in better,it this true?It's been a long time since i had to break in a engine so i don't want to screw this up and get the best possible performance out of it.

Also the oil that comes from the factory is just good old regular quicksilver oil right?Is it a special breakin oil or will any oil work?I think i want to break mine in with full synthetic oil,i don't think it will hurt it at all.I know it's been a on going thing whether it's safe to use synthetic oil for breakin or not.I can't see how it can hurt it.Also there has been no engine failures i have heard of when breaking in a engine with full synthetic oil or conventional oil so i would think both would be safe to use.
 

ondarvr

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Apr 6, 2005
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11,527
Re: Breaking in a new merc outboard

I'm sure the people suggesting other methods are much smarter and have far more experience with breaking in Mercury products than any engineer that helped to design the engine.

Don't over think it, just follow the book.
 
D

DJ

Guest
Re: Breaking in a new merc outboard

I'm sure the people suggesting other mothods are much smarter and have far more experience with breaking Mercury products than any engineer that helped to design the engine.

Don't over think it, just follow the book.

Ditto.
 

boater1234

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Re: Breaking in a new merc outboard

Ok i will just go by the book as best as i can.Once i breakin the motor for a full 10hrs i know i must change the lower unit oil and engine oil and probally the plugs.Is there anything else i need to do after that or will it be ready for wot.If there is anything i need to do besides that please let me know thanks.
 

ondarvr

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Re: Breaking in a new merc outboard

Again...the manual will tell you.
 

boater1234

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Re: Breaking in a new merc outboard

The manual does not tell you everything.That is why if someone has some experience with these new 4strokes i would be gratefull for any info.I have broke in 2 2strokes with no problem but a 4stroke is a whole different animal.I have heard things like vales need to be adjusted.I have read somewere in a thread that they very seldom need any adjustment,if i'm not mistaken tohatsu guru said usually one of a thousand may need it so it sounds like a way for marinas to make money.I have also heard a ton of dealers say the same thing.I will just figure it out for myself,i was just wondering if anyone had first hand experience with small 4strokes that could lend a helping hand.No big deal.
 

5150abf

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Re: Breaking in a new merc outboard

I think what they are trying to say is to follow the manual as the engineers know way more than most of us here and I am sure you can find someone that will tell you to run it full throttle with a bottle of vinegar in the gas but you may not want to take that advice.

The manual will cover break in and the first service and I would follow what they say to do, people will tell you to try all sorts of things but you don't want to do all of them, the manual won't lead you wrong or void the warranty.
 

boater1234

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Re: Breaking in a new merc outboard

I have been doing alot of researching on oil,i have found a ton of sites with many people saying there outboard makes oil.The biggest thing was from not running it hard and moisture getting into the oil and the engine not getting hot enough to burn it off.Is this a normal thing on 4strokes.I guess that is why they say don't fill your oil all the way up to the highest hole of the dipstick.So you can leave room just in case it does that i would assume.Is this common with any 4stroke outboard?I guess the way to avoid it is run it hard as possible and keep the idleing down as much as possible.Is there anything else to this oil making i need to be concerned about?They also said it is very common on breakin,is this true and normal?
 

TOHATSU GURU

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Re: Breaking in a new merc outboard

Should you follow the manual? Yes. Will you follow the manual? Probably not. Most people get impatient with the break in procedure after an hour and begin operating the engine without any regard to RPM. So the question becomes, does that hurt anything? And the answer is a qualified no. So the next question becomes, why have a break in schedule at all? And the answer is twofold for two unrelated reasons: First, the piston rings need to wear into the block over a wide RPM range rather than at one particular point. Secondly, the manufacturer wants you to run the engine gently for the first few hours so that if it does have a problem it will present itself, at a low enough RPM, so that it may avoid a catastrophic failure.

Run 10w30 oil and change it after the first 5 hours. The engine will gain oil so periodically drain a little off. Its normal for any 4-stroke and is unavoidable for most people who idle for any amount of time.

And lastly: Enjoy your engine, stop being paranoid about potential problems and spend some time out on the water rather than being on the web:)
 

e10

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Re: Breaking in a new merc outboard

How does an engine make/gain oil?
 

ondarvr

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Re: Breaking in a new merc outboard

In my part of the world we use our small 4 strokes for trolling, this means idling for hours on end, for days at a time.

The typical issue is they are set up very lean at the factory, this can result in them being very cold blooded and/or have a poor idle. There is a cap over the adjustment screw that needs to be removed and then you can set it correctly, not every motor needs this, but many do.

Making oil is from fuel getting past the rings and diluting the oil, if you see the level getting higher, change it. Gas in the oil will degrade it. High RPM's can help evaporate the fuel.

Water in the oil (milky and thick) is from condensation forming and never evaporating, for extended trolling this can be an issue. The fix is a warmer thermostat or running it at high RPMs for a period of time so it actually becomes warm enough.

While each brand of small 4 stroke will be slightly different, these are the general problems and solutions.

With a 20 on a small boat you may never see any of these issues, I assume you will be running it out to the fishing area at speed and the same thing on the return trip, depending on the length of the run, both making oil and water in the oil may be taken care of.

Like TG said, the chances of having a problem by not following the break in procedure exactly is pretty slim, but if you are worried, follow them to the letter and you will be fine.
 

JimS123

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Re: Breaking in a new merc outboard

The boats I use most are an I/O, an OB and an IB jet. All were bought new and all were broken in according to the manufacturer's recommendations. To the letter! If it said don't run WOT until X hours, I didn't All run very smoothe now at all speeds, and idle particulary good. The I/O now has 1250 hours, the IB about 400 and the OB 600. After breakin the OB ALWAYS runs at idle.

I travel often and rent boats quite frequently when I have a day off. I've even rented ones with the same engines as mine. I also have quite a few friends who aren't so meticulous about following directions, and I ride on their boats often as well. Nobody has smoother running engines than mine, and my mechanic even made that remark.

My IB (4-stroke) came from the factory with synthetic oil. The service manager changed it to mineral oil before delivery, and changed it back at the 10 hour checkup. He said that was the preferred way, based on his experience. I can't comment one way or the other, but what I can comment on is the flawless performance of the engine. NOT breaking in an engine on synthetic is a common recommendation.

Just saying.....(as they say....LOL).

In most cases it won't matter anyway, since most boaters trade in, upgrade, or get bored very quickly, so by the time the motor greanades they don't own it any more. Its the guy that buys second hand that has to worry about it!
 

boater1234

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Re: Breaking in a new merc outboard

Well i will follow it as close to the t as i can.I will do what it says if it will help the performance or make it run better.I was just worried about the making oil part of it as i have seen tons of threads were their 4stroke outboard was making oil.Most of the time my spots do require wot to get there or it would take forever to get there.I do very little trolling if any.Usually i go to a spot and turn the motor off,then start it up again to wot when leaving spot to spot.Sometimes i need to go idle speed in canals with no wake zones but other then that hardly ever do i idle.I idle from the boat ramp to the gulf and open it up which is usually within 5 minutes.Also how long should a little motor like this warm up before i go wot,like in the morning i put the boat in the water and start the motor,how long does it take to warm up?It says the breakin period is 10hrs.I will use the oil provided in the box,then switch over to my synthetic oil after the full breakin.I just hope this motor performs good.It sould be any day now,just waiting for the call.
 

TOHATSU GURU

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Re: Breaking in a new merc outboard

Do not run synthetic oil in your engine...No advantage to it as it makes the engine run too cool. Its also not cost effective as you change your engine oil every 25 to 50 hours on an outboard. Since outboards are raw water cooled, operating temperature attainment will very depending on water temp, air temp and rpm. In Tampa figure 3 minutes at 82 external temp, 72 water temp and 1300 RPM.
 

boater1234

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Re: Breaking in a new merc outboard

I'm not saying your wrong as you have been giving me great advice from the start but why do so many people do it with never ever having a problem with their outboards.Also yamaha just came out with a full synthetic for all their 4stroke outboards so i can't see how it would hurt it.If yamaha makes it why not use it,i'm just asking a question here not debating you as you are way smarter then me about the way outboards work.I wouldn't think yamaha would make a product that would hurt your outboard.I know i am running a merc but a 4stroke is a 4stroke right?It's fcw rated oil which is marine certified right?Plus the merc oil is just as expensive as any other oil so there would be no advantage or disadvantage as far as price.Even with the amount of wot i will be running you think the engine won't get hot enough with synthetic oil in it?If you think there is really no advantage or disadvantage then i will just run the merc oil,they sell it at walmart for $6 a quart can't beat that.
 

sschefer

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Re: Breaking in a new merc outboard

To the original question -- Why in the world are you even asking such a dumb question. Oh wait, you like warranty repair rejection.. Now I get it.
 

boater1234

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Re: Breaking in a new merc outboard

Also do you suggest using a water/fuel seperator with a small motor like this?I am using non ethanol 93 octane gas from the marina down the road from me.Should i just use it anyway or just leave it alone.I will use every advantage i can get to keep my outboard running as good as possible.The main reason i was told to use synthetic oil in my outboard was it helps from getting any carbon builup and also lubricates better.
 

boater1234

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Re: Breaking in a new merc outboard

To the original question -- Why in the world are you even asking such a dumb question. Oh wait, you like warranty repair rejection.. Now I get it.
As long as it is API OR SAE certified you can use any oil you want.Also i have read almost every manual that i have gotten when i sell motors and not one ever mentioned your warranty would be voided if you use synthetic oil.So i think you may want to read up a little more before saying it's a dumb question.
 

JimS123

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Re: Breaking in a new merc outboard

Well i will follow it as close to the t as i can........Usually i go to a spot and turn the motor off,then start it up again to wot when leaving spot to spot.

Makes no sense at all. Either you do it or you don't. No reason you can't. You go WOT because you WANT to, not because you HAVE to.

I usually go WOT all the time too. But when I broke the motor in I didn't....LOL. That's called breaking it in, not breaking it.

Or, just do as you please and sell her in a couple years. The next owner won't know the difference anyway.
 
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