How to break in a new bike.

[Whip]

I have never felt manufacturers give us the best instructions on how to break in a new motor. 

 

I had two KTM 950/990s. The first one I broke in just like the manual said and it burned oil it's entire life. After reading more about it on the second bike I broke it in more like this video suggested and it never burn an once of oil ...EVER!

 

BTW....I think I have watched everyone of this guys videos ... very entertaining.

 

 

 

[Antimatter]

MC Garage did an interesting comparison of two motors broken in by the book and with hard throttle inputs.  The upshot is that with a modern, Japanese motor, the old low-rpm approach is more aimed at the rider than the motorcycle itself.

[Hosstage]

The age old argument.

I am not a fan of low rpm break in. I think it hurts as much as pounding on it when new. I go with the "ride it normally" approach. I certainly don't like lugging a motor, new or not. I think that's the problem with the low rpm approach, people take that to mean short shifting and lugging.

I ride it in its normal operating rpm range, an occasional higher rpm run when warm, I will even run it close to redline once after a few hundred miles, no long interstate runs at first but no need to avoid the interstate for short runs. I also run it up and down the rpms in gear to out backpressure on the pistons. change oil early the first couple of times.

The video seems to agree mostly with my methods.

Just me, of course. Everybody has their way.

As many answers as oil threads!

[dirtrider]

I have never felt manufacturers give us the best instructions on how to break in a new motor. 

 

Probably so but remember there is more to beak in properly than than JUST the engine.  There is the final drive gear set, the brakes, the transmission gears, etc.

 

Engine wise then lots or varying RPM's, frequent cool-downs, LOTS of higher RPM over-run cost-downs with closed throttle (not max RPM though) , no lugging & no mono speed long free-way runs. 

 

Final drive gear tooth contact break-in  then vary the road speeds, light accels/light coast downs, no long run wide open full torque runs. No long freeway runs until some miles on the hypoid gears. 

 

On the transmission gear tooth contact break-in ,  light runs in all gears with light load shifting & no one-gear long runs, numerous light decels. 

 

Find a compromise on the above. 

[RTinNC]

10 hours ago, dirtrider said:

I have never felt manufacturers give us the best instructions on how to break in a new motor. 

 

Probably so but remember there is more to beak in properly than than JUST the engine.  There is the final drive gear set, the brakes, the transmission gears, etc.

 

Engine wise then lots or varying RPM's, frequent cool-downs, LOTS of higher RPM over-run cost-downs with closed throttle (not max RPM though) , no lugging & no mono speed long free-way runs. 

 

Final drive gear tooth contact break-in  then vary the road speeds, light accels/light coast downs, no long run wide open full torque runs. No long freeway runs until some miles on the hypoid gears. 

 

On the transmission gear tooth contact break-in ,  light runs in all gears with light load shifting & no one-gear long runs, numerous light decels. 

 

Find a compromise on the above. 

LOL ... that's how I broke in my last few bikes and that was the guidance my dealer gave me but honestly THAT is pretty much how I ride all the time anyway.  So I just ride a new bike the way I always ride.   I just watch the very high RPM runs but for me those are rare anyway. 

[John Ranalletta]

8 hours ago, RTinNC said:

LOL ... that's how I broke in my last few bikes and that was the guidance my dealer gave me but honestly THAT is pretty much how I ride all the time anyway.  So I just ride a new bike the way I always ride.   I just watch the very high RPM runs but for me those are rare anyway. 

 

In 1969, upon graduation, I bought a '69 Ford Torino GT, 350 c.i., 4 spd.  $8k new, btw.  I asked George Glasscock, the dealer, "How should I break this in?".  He replied, "Take it out in front of the dealership, rev it up and drop the clutch.  If it breaks, I'll fix it."  I didn't do that.  I loved that car, man.

[BrianT]

I definitely don't baby a motor on break in.  I just follow the no steady RPM rule.  Up and down through the gears and always accelerating or decelerating, no steady throttle.  I try to avoid highway/freeway use.  My bikes never loose/burn oil.

 

I never took cool down breaks during break in like the video suggested.  I guess heat cycles on the metal could make a difference. 

[Hosstage]

10 hours ago, John Ranalletta said:

 

In 1969, upon graduation, I bought a '69 Ford Torino GT, 350 c.i., 4 spd.  $8k new, btw.  I asked George Glasscock, the dealer, "How should I break this in?".  He replied, "Take it out in front of the dealership, rev it up and drop the clutch.  If it breaks, I'll fix it."  I didn't do that.  I loved that car, man.

Not to nitpick, but you know how car guys are!  No 350s in Ford's, probably a 390, maybe a 351. I was a Ford guy for a long time, loved the 390 motor. And really liked the '69 Torino with the 4 speed, still a cool car. Kind of wish you still had it, don't you?

[John Ranalletta]

12 hours ago, Hosstage said:

Not to nitpick, but you know how car guys are!  No 350s in Ford's, probably a 390, maybe a 351. I was a Ford guy for a long time, loved the 390 motor. And really liked the '69 Torino with the 4 speed, still a cool car. Kind of wish you still had it, don't you?

351 for sure.  Miss it still.  Started having kids and traded it in for a 2-door, red, Ford Pinto 

The exact car:

 

 

 

It was rear ended but didn't burn.  Bought a Pinto wagon with insurance money.  It did burn.

[Hosstage]

Good looking machine!

Not sure what to say about the Pinto......

[roadscholar]

Had several really good engine builders do the motors in my 911 racecars. They all said pretty much the same thing, warm it up a couple laps then let it rip : )

[Joe Frickin' Friday]

On 1/17/2021 at 1:39 PM, dirtrider said:

Engine wise then lots or varying RPM's, frequent cool-downs, LOTS of higher RPM over-run cost-downs with closed throttle (not max RPM though) , no lugging & no mono speed long free-way runs. 

 

 

 

Years ago Dick Frantz did a good write-up on breaking in a new engine.  It was hosted here on the site, but it seems to have been lost in the most recent upgrade.  If we're lucky, someone somewhere will have saved a copy, but absent that, the basic points that I remember are as follows (not terribly different from the video Whip linked to, and what's been mentioned by others upthread). 

 

When the rings/bores are new, they don't seal well, so excessive blow-by is going down past the rings, and excessive oil is coming up.  If you baby it during this period, you set the stage for long-term oil consumption and wear: the blow-by roasts the oil on the bore surface and cokes up the grooves that would otherwise serve as tiny reservoirs of lubricant.  Your goal is to use this early period to deliberately wear the rings the bore surfaces to match: you need to have the rings scrape off the peaks of the microscopic ridges on the bore and let the oil wash away the wear material.  So you have to push the rings against the bore by applying some engine load.  But you want to do this in intervals, and you want to avoid high piston speeds, otherwise you can develop high temperatures (through a combination of blow-by under load and frictional heating at high RPM and load) that can cook the oil into the microscopic grooves in the bore and also smear the wear particles into the bore/rings.   

 

So you get out on to an empty road, because your speed is going to vary all over the place and you don't want to annoy other motorists.  And once you're there:

 

1. Start at modest RPM in a middle gear.  

2. Apply maybe 50% throttle, and accelerate until the engine is spinning at maybe 2/3 of redline.  During this accel period, the elevated gas pressure is forcing the rings against the bore, machining the peaks off of the microscopic honed ridges on the bore.  

3. Once at 2/3 of redline, reduce throttle to hold speed for a few seconds, and then close the throttle.  With load removed, the rings are no longer scraping the bore so harshly, and the engine is now pulling a strong vacuum during the intake stroke, drawing oil upward past the rings.  Temperatures drop, and the oil helps wash away the wear material that was just created.  

4.  Once you've coasted back down to modest RPM, repeat steps 2-3.  

 

After you've done this for a few hundred miles, the bore and rings start to be worn enough to where they'll tolerate higher piston speeds without overtemping.  And at this point you start to want higher piston speeds, because inertial loading of the crank, rod, piston, and the various oil films in their bearings will make the piston rings travel that last thousandth of an inch along the bore.  You need to wear-in that part of the bore too.  If you don't, you can end up with a tiny microscopic "step" in the bore there, and encountering that a few thousand miles later when you finally run it to redline (after never previously going past 5000 RPM) can damage the ring.  So anyway, after repeating the 1-4 sequence above for a few hundred miles, you start to go to higher loads, and higher RPMs.  Contrary to what the manual says ("after 600 miles GO NUTS"), you want to make this a gradual transition.  

 

Dick's claim was that although you can operate BMW engines without speed/load restrictions after 1000 miles or so, their extraordinarily hard Nickasil bore lining doesn't fully wear in for several thousand miles.  

 

Anyway, that's what he had to say about it.  It all seemed fairly sensible to me.  

[realshelby]

Race engines costing $40,000+ are a good place to learn about "break in". Engine builders live off their reputation. Yes these engines are precision built but they DO need a break in process and it shows that it does in power readings. These are ready to put in a vehicle and run at race loads when you get them. They will also have a dyno sheet with all power readings...

These are put on an engine dynamometer where they have full cooling systems. Started and run at 2-3,000 rpm for 20-30 minutes. Usually no load or rpm change. This first run is to break in camshaft, lifter, and rocker to valve surfaces. Then it will have the valve covers removed ( after cooling a bit ) and the second set of valve springs installed on each valve. Then it will be run at different load and rpms for several minutes while fuel/air and timing is adjusted. Then it goes to step pulls where it will be run full throttle up to say 5000 rpm. Then idled down and looked over. Then to 6,7,8, and to full operating rpm. If all looks good it is usually allowed to cool down and any slight adjustments are made.  Then a few full load full rpm runs are made and it is ready to go to the customer. There is often several horsepower gained during the break in process, not all done with tuning adjustments. When the pulls start leveling out in power, it is considered broken in. So there IS merit in full load operation for short periods. I do believe the cool down or rest periods between these loads are critical, but like many things it is hard to prove what is exactly the best way.

[Hosstage]

I hear often about shops doing motor upgrades, do a few heat cycles, hand it over to the customer to put 500 miles on it, then bring it back for a tune.

If that is the standard operating procedure for that shop, find another shop.

[Antimatter]

One thing I forgot to add was that most major motorcycle manufacturers run their motorcycle to redline on a dyno before they leave the factory.  I know personally that Ducati will bounce theirs off the redline several times before the bike is parked on the floor of the shipping area.  So, it really doesn't matter if you keep the bike's rpm's low during your break-in period - the bike's engine has already seen the rpm limit at least once before it arrived at the dealer.  Whether your break-in practice involves back streets, a dyno, or some combination of sage and holy water - it doesn't really matter.  Do what works for you.  Now, it's a different story if you're talking about rebuilding an antique engine, or if you've gotten your hands on something that's been in a crate since the 1970's.  But for the modern stuff, I don't think it matters.

[lkchris]

 

On 1/17/2021 at 7:30 AM, Whip said:

re:  I have never felt manufacturers give us the best instructions on how to break in a new motor. 

 

 

This is because engine break-in is a thing of the past.  Ancient history.

 

In 2006 I was able to tour the facility where Mercedes AMG engines were hand assembled.  At the end of the line and after the technician affixed his signature plate, the engine was filled with fluids and attached to a fixture that spun the engine electrically.  The engine did not start.  At this point, break-in had occurred.

 

For reference, look up "plateau finishing" applicable to the engine rebuild world.

 

Also read this article

 

https://en.wikipedia.org/wiki/Break-in_(mechanical_run-in)

 

A related misconception that occurs among BMW fans is that engines are initially filled with nonsynthetic motor oil to facilitate break-in.  This notion is ridiculous on the face of it, as if nonsynthetic oils were so bad as to facilitate engine wear, they would never be used anywhere except for that purpose.  Its an economy measure, as BMW specifies an initial 600 mile oil change in any event.  Corvettes, Mercedes, Porsche, etc. are factory filled with Mobil 1.

 

The world is changing ... yes we all love our Dads and '57 chebbies, but that's nothing but irrelevant nostalgia.