breaking in new 4stokes

the_anarchy16

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Mar 25, 2008
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was wondering when breaking in a new 4stroke if this must be done in gear and on the water. I know that large lengths of time must be spent at different speeds but i was wondering if i need to have the boat in opperation. Can this be done in a bucket? I have a large drum that i do my flushes and what not in and i was wondering if this would do. Do not have a lot of time and 10 hours putting around the river in high chop would not be fun. Thanks
 

blouderback

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Apr 6, 2006
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Re: breaking in new 4stokes

No need to "putt" around. You can run the motor normally for the first 5 hours, just no long term idling and no WOT. After the first 5 hours, you can go WOT for a few seconds at a time, and then after 20 hours, run it like you stole it!

I would not do it in a bucket. The motor needs to be under load to get the rings to set properly. Again, too much idling will not get this done, and I wouldn't want to run the motor at 3000 - 3500 rpms in a bucket.
 

JB

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Re: breaking in new 4stokes

What is a srum??
 

CWCW

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Re: breaking in new 4stokes

Is there a certain time frame you would have to finish the break-in peroid in? Can you cruise around in the water for a month or two until the break-in hours have been finished (assuming you follow the set rules) or do you really need to try and complete the break-in hours in as short of a time span as posibble?
 

Don S

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Re: breaking in new 4stokes

The breakin should be done UNDER LOAD, on the water, not in a tub or on a flusher.
 

JB

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Re: breaking in new 4stokes

Okay. Senior moment. That's a misspelled drum.

Dang, I wish people would proofread and edit their posts before they post 'em. It's hard enough to just see the post without having to challenge my feeble old brain to figure out what the poster meant. :(
 

Silvertip

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Re: breaking in new 4stokes

Is there a certain time frame you would have to finish the break-in peroid in? Can you cruise around in the water for a month or two until the break-in hours have been finished (assuming you follow the set rules) or do you really need to try and complete the break-in hours in as short of a time span as posibble?

Hours are hours: If you get the 20 hour break in done in one day you are done. If it takes a month to get 20 hours of run time you aren't done until then.
 

BF

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Re: breaking in new 4stokes

I've got to do a 10 hour break-in on my 4-stroke Merc this spring. Doesn't sound too bad, until I think about how long 10 hours of running around in an aluminum utility boat really is. My normal use for a weekend is probably a total of 30-45 minutes at WOT, 5 minutes at some intermediate throttle setting, and 6 or 7 hours of idling.

Not to hijack the thread, but a Q about one of the responses...

So, do I understand correctly that the engine should not be idled for extended periods during break in? Does that mean that it does some harm, or just shouldn't be counted in the break-in hours? I would prefer to interrupt my break-in "cruising" with some hours of trolling, but if that's not a good idea, I won't.
 

TOHATSU GURU

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Re: breaking in new 4stokes

Here's a quick tip for break-in. Cut the times in half on the schedule. It will not hurt anything. Manufacturers have an extended break in time so that if you have a catastrophic failure you will probably not be running at WOT. That saves them money on the rebuild as you are less likely to have a cascading failure that that wipes out multiple parts.
 

GregE

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Re: breaking in new 4stokes

I've got to do a 10 hour break-in on my 4-stroke Merc this spring. Doesn't sound too bad, until I think about how long 10 hours of running around in an aluminum utility boat really is. My normal use for a weekend is probably a total of 30-45 minutes at WOT, 5 minutes at some intermediate throttle setting, and 6 or 7 hours of idling.

Just did this myself toward the end of last summer. 9.9 Merc 4 stroke. And you're right, 10 hours doesn't sound like much, but it is! I bass fish on several lakes about 800 acres each and it's amazing how little time I put on that motor each time out. I'm only halfway into breakin as I begin again this spring.
 

drewmitch44

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Re: breaking in new 4stokes

What is a srum??


Why do you ask that? Noone said the word srum. I dont get it JB are you asking what one is? Cause ive never heard of that and noone has said anything about it in this post.
 

Silvertip

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Re: breaking in new 4stokes

Extensive idling does not load the engine enough to properly seat the rings. Suzuki recommends 5 minute warm ups, then in-gear/idle for the first 15 minutes. Then 1:45 at 3000 RPM. Next hour at 4000. Next 7 hours at any speed as long as full throttle use does not exceed 5 minutes at any time.
 

rickdb1boat

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Re: breaking in new 4stokes

Here's a quick tip for break-in. Cut the times in half on the schedule. It will not hurt anything. Manufacturers have an extended break in time so that if you have a catastrophic failure you will probably not be running at WOT. That saves them money on the rebuild as you are less likely to have a cascading failure that that wipes out multiple parts.

And when it blows up and they check the computer to see how it was run during break-in, you could have serious problems...
 

BF

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Re: breaking in new 4stokes

Extensive idling does not load the engine enough to properly seat the rings. Suzuki recommends 5 minute warm ups, then in-gear/idle for the first 15 minutes. Then 1:45 at 3000 RPM. Next hour at 4000. Next 7 hours at any speed as long as full throttle use does not exceed 5 minutes at any time.

OK, so do you take that to mean that spending the majority of the last 7 hours at idle would be acceptable? (idle would count as "any speed" and is not WOT) I've always heard to vary the rpm's during break-in periods and not stay too long at any particular rpm setting. (?)

In my merc manual it says not to exceed 1/2 throttle for some period, then not to exceed 3/4 except for occasional brief bursts of WOT. Etc... I always took that to mean that it should be run AT around 1/2 or 3/4 throttle during those periods (not just idling around). So what you say about seating the rings makes sense.

I was surprised to see no suggestion in the manual that an oil change should be done following the break-in hours. Seems like common sense to change the oil & filter after break-in to get out any filings/debris that were there either from manufacturing or produced as things seat. (?) So, I'm intending to do that anyway.
 

TOHATSU GURU

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Re: breaking in new 4stokes

As there is no legal contract between the manufacturer and the consumer where the consumer is bound to follow the schedule, I don't think it would be an issue. Only a few EFI 4-strokes even have a CPU that can map a RPM history and it would be a rather rare occurance where a manufacturer would try to deny coverage on so flimsy an excuse. That's an opinion though and I guess it is possible in theory if the manufacturer has a bee in their bonnet.
 
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Silvertip

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Re: breaking in new 4stokes

Seven hours at idle would not be a good scenario in my view whether the motor is broken in or not. Prolonged idle is not good for any engine whether it's two stroke, four stroke, carbed, EFI or DFI. Ever heard of "making oil"? Four strokes are noted for it. Over propping, extensive idle, and over cooling are two good reasons for it. Get the boat on plane during break in and follow the recommendation. It's ok to go wot (not wide open rpm) to get on plane. Long before most of you were able to drive a car, the recommended method for seating rings after a rebuild was to drive at 25 - 30 MPH in high gear and floor it until you hit 50 MPH. Slow to 30 MPH and repeat several times. Then no constant speeds for the remainder of the break in period. Modern rings and manufacturing allows running cars reasonably hard right out of the box -- like an E-tec. As for the after break in oil change, Suzuki says change oil and filter at the 20 hour point and there is even an indication on the the monitor/tach that tells you when that is. Running time is also indicated on the tach during the startup cycle.
 

BF

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Re: breaking in new 4stokes

I hear what you're saying about 7 hours at idle being no good in general. During my normal use, that idling would actually be interrupted fairly often by bursts of higher speed running (moving to different spots). Every 2-3 hours there would be a more prolonged high speed run. Time-wise though, I expect that over it's life this motor will spend much more of it's time at idle than some other throttle setting. As for the making oil thing, yes it's something I'll watch for. Makes me think that the break in is particularly important to get good ring seating.

Q: Do you think improper break-in commonly contributes to the "making oil" problem? It'd make sense I think. (?)
 

CWCW

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Re: breaking in new 4stokes

(Q: Do you think improper break-in commonly contributes to the "making oil" problem? It'd make sense I think. (?) )

To answer your question BF,
In a four stroke, if your motor does not get the proper breakin and the piston rings do not seat properly you can get gas that will leak by the rings and fall into the crankcase. This could cause "making oil". You should be able to see the gas droplets floating ontop of the oil in the oil pan when you change the oil and you should be able to smell the gas in the oil.

I only learned about the other way of 4strokes making oil a couple of months ago. If the piston rings are seated properly and you still are making oil then this is caused by over cooling the engine which is stated above. People who troll for excessive hours may see this type of "making oil" caused by condensation of water vapor in the crankcase. I would venture to say this happens more up in the northern areas where the water temp is much cooler than where i am in Texas. To fix or lessen this problem of making oil, I have been told that after trolling for extended hours, you can run the engine at higher rpms for a period of time to get the engine up to normal (hot) temperature levels so that the condensated water in the crank case can be evaporated before pulling the boat out of the water.
 

Woodnaut

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Jul 4, 2007
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Re: breaking in new 4stokes

The manufacturer's recommendation for breaking in my 90 hp Yamaha four stroke was to run at 2,000 RPM for 1 hour, run at 3,000 RPM for 1 hour, and then run at any other speed for the remaining 8 hours EXCEPT do not run at WOT for more than 5 minutes at a time during the remaining 8 hours.

There are probably a couple of things going on during the break in period with the bearings and other surfaces, but seating of the piston rings is definitely happening and is important. I have heard reports of running four strokes too lightly during break which can result in the engine "making oil" later. (See posts above.) At the same time, I have heard some folks suggesting that one should "run it like you stole it" during break in to avoid this problem.

Being an engineer type, I tend to think the manufacturers know what they are talking about so I went by the book. ;) Not only that, but these engines are expensive so I'm going to do everything I can to keep it within warranty and extend it's life into the year 3000 if possible.
 
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