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SpecialEd

Weird Engine Break-in Protocol

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Recently read this on another moto chat board, and would love to hear thoughts from those of you who are tech-oriented. This break-in protocol seems *severe* to me. I will soon be riding a restored vintage Honda with a brand-new engine built from the ground up, and want to break it in properly. I seem to remember that a gentle break-in was almost always recommended.

Thoughts??

ttp://www.mototuneusa.com/break_in_secrets.htm

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I don't have an answer, except that it looks like an excuse to buy 2 engines and see. Knowlege is power!

 

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I just hit 68 miles on my new ride. It didn't get a gentle ride.

20190429_155401.jpg

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There almost as many arguments about break-ins than their are about oils. I think most people say to avoid revs at or above redline and don't hold the same rpm for extended periods. After that, opinions vary wildly.

Edited by ScubaCinci

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strike a balance between the two schools lol 

first 150 -200 mile keep max rpm reasonable sane low range but varying. (avoid highways and slabs etc) then change oil and still keep varying but at higher range of RPMs. change oil by 500 miles and go to town and unleash hell. 

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Go ahead and beat on it out of the box. I built a hopped up cb750 a few years ago and went straight to abusing the shit out of it and it runs just fine. 

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Wtf is break in period? My bikes first couple hundred miles were almost all slab and definitely wasn't going easy on the thing... Turned out just fine. 

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From what I've read, the primary purpose of a relatively gentle break-in period is to optimize contact between piston rings and cylinder walls. Apparently, this is why cylinders are honed/etched in a fine cross-hatch pattern which, as I understand it, gradually files down the contact point between rings and cylinder until both are smooth and as perpendicular to each other as possible.

HOWEVER, none of the responses from y'all have indicated that this type of break-in is needed, so I guess I'm back to square one . . .

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People get all hung up on the break in and then sell the bike with less than 10k miles on it. A less than ideal break in may cause longevity issues. If you don't plan on keeping the bike long enough for that to be a factor, there are plenty of other things you can worry about that will have a greater impact on the health of the bike.

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9 minutes ago, ScubaCinci said:

People get all hung up on the break in and then sell the bike with less than 10k miles on it. A less than ideal break in may cause longevity issues. If you don't plan on keeping the bike long enough for that to be a factor, there are plenty of other things you can worry about that will have a greater impact on the health of the bike.

Good point, and maybe this is why so many folks don't do this type of break-in. I am planning to keep my bike for many years, so I'll take it easy the first few hundred miles and change the oil frequently during that time.

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1 hour ago, SpecialEd said:

From what I've read, the primary purpose of a relatively gentle break-in period is to optimize contact between piston rings and cylinder walls. Apparently, this is why cylinders are honed/etched in a fine cross-hatch pattern which, as I understand it, gradually files down the contact point between rings and cylinder until both are smooth and as perpendicular to each other as possible.

HOWEVER, none of the responses from y'all have indicated that this type of break-in is needed, so I guess I'm back to square one . . .

A lot of it is insurance based as well. Manufacturers (their lawyers) would rather a person take it easy and get used to the bike before going out hammer down and getting killed because they never learned where the brakes were. They can then point to the manual and say "we said to break it in slow and easy, not our fault". 

 

Race engines are broken in on the dyno. The biggest thing is making sure the rings seal correctly, which can be accomplished either way. Just don't sit there pinging off the rev limiter with no load on the piston. Variable load is what you want. 

Edited by what

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8 minutes ago, what said:

A lot of it is insurance based as well. Manufacturers (their lawyers) would rather a person take it easy and get used to the bike before going out hammer down and getting killed because they never learned where the brakes were. They can then point to the manual and say "we said to break it in slow and easy, not our fault". 

 

Race engines are broken in on the dyno. The biggest thing is making sure the rings seal correctly, which can be accomplished either way. Just don't sit there pinging off the rev limiter with no load on the piston. Variable load is what you want. 

All of this makes sense to me, especially "breaking-in" owners of new bikes as well as the bikes themselves. Never even thought about that!

As far as heat buildup during break-in miles, is this a concern, too? My rig will have an oil cooler, and I was told by the guy doing the build that I shouldn't let the engine overheat; just stop every few miles to allow the engine to cool down.

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1 hour ago, SpecialEd said:

I am planning to keep my bike for many years, so I'll take it easy the first few hundred miles and change the oil frequently during that time.

A few hundred miles of being cool in the grand scheme of things isn't going to change your life. You can get this done in one day. No harm in doing it that way and maybe it helps. 🤷‍♂️

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11 minutes ago, SpecialEd said:

All of this makes sense to me, especially "breaking-in" owners of new bikes as well as the bikes themselves. Never even thought about that!

As far as heat buildup during break-in miles, is this a concern, too? My rig will have an oil cooler, and I was told by the guy doing the build that I shouldn't let the engine overheat; just stop every few miles to allow the engine to cool down.

Overheating is bad. If you have always broken your engines in the low and slow method, there's nothing wrong with continuing to do so. 

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14 minutes ago, Tonik said:

A few hundred miles of being cool in the grand scheme of things isn't going to change your life. You can get this done in one day. No harm in doing it that way and maybe it helps. 🤷‍♂️

Okay, good. I hate the thought of wasting most of a riding season breaking this thing in.

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On 5/1/2019 at 8:55 AM, motocat12 said:

I don't have an answer, except that it looks like an excuse to buy 2 engines and see. Knowlege is power!

 

Okay, after watching this great video, I'm solidly of two minds: beat the hell out of your new moto or don't, it apparently doesn't matter during break-in :dunno:

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6 hours ago, what said:

A lot of it is insurance based as well. Manufacturers (their lawyers) would rather a person take it easy and get used to the bike before going out hammer down and getting killed because they never learned where the brakes were. They can then point to the manual and say "we said to break it in slow and easy, not our fault". 

 

Race engines are broken in on the dyno. The biggest thing is making sure the rings seal correctly, which can be accomplished either way. Just don't sit there pinging off the rev limiter with no load on the piston. Variable load is what you want. 

This is the way I'm going to do it. As you suggest, I'll not over-rev and will vary the load I put on the engine/drive train--AND change oil frequently/check for the presence of stardust in the crank filter.

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I rode my vfr to the dealer and my brand new bike home.... Each got equally thrashed, the final voyage and the maiden voyage 😂

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54 minutes ago, Steve Butters said:

I rode my vfr to the dealer and my brand new bike home.... Each got equally thrashed, the final voyage and the maiden voyage 😂

This is the correct protocol

 

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1 hour ago, Gixxus Christ! said:

This is the correct protocol

 

fails the N+1 rule.

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Actually, almost all factory engines are initially broken in on test stands, before crating and shipping, or assembly. This is to avoid potential "thrashed to death" within the warranty period. Break in strategies vary per the specifications of the engine assembly. Tight tolerances requires gentle and varied. Loose is whatever... The important part is the early oil changes. Tons of metallic crap is produced in the first few miles. Dump it. And the filter.

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this reminds me that I saw a brand new chevy impala still had the wrap on the bumpers smoking out of the tail pipe as the guy was driving it down the expressway. lol  pile of junk!

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back in the day... when I worked in the early years at a Honda shop, those early bikes were tight from the factory. Several engines were ruined on demo rides, when they were thrashed before they were ready for that. I do not think this happens anymore from the factory. I haven't heard of such happening. But if you rebuild your own engine, and it needs a gentle break-in, by all means be gentle. I have always been gentle on the break-in for an engine that I re-built myself.

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In my opinion it's better safe than sorry.  I broke my R6 in per the manual.  When I sold it with 50k street miles and maybe 400 track miles on the engine the thing was still pulling hard and didn't use any oil.  Not an oz of oil.  Didn't smoke, didn't make noises.  That was in 2014.  The person that bought it is still riding it with over 70k miles

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2 hours ago, serpentracer said:

In my opinion it's better safe than sorry.  I broke my R6 in per the manual.  When I sold it with 50k street miles and maybe 400 track miles on the engine the thing was still pulling hard and didn't use any oil.  Not an oz of oil.  Didn't smoke, didn't make noises.  That was in 2014.  The person that bought it is still riding it with over 70k miles

Well, this is certainly convincing evidence. I'm not going to chance it either. Slow and easy can't hurt for those first few months, and that's what I'm going to do. Frequent oil changes are cheap insurance, too. I've put a lot of money into the bike I'm having built--and about half the cost was a custom-built engine.

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