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Engine break-in procedure

Discussion in 'Maintenance and Servicing' started by Dzyan, Apr 30, 2013.

  1. Hi all

    I'm putting a 125cc pit bike engine in my postie (yeah yeah its pint sized compared to some of your rides) and I decided to ask google the correct break in method for bike engines.

    Expecting to see a lot of "500km @ 1/3 throttle max" I was amazed that I came across this instead.

    Anyone here able to confirm/deny this with first hand results?

    Or would someone be willing to donate 600 bucks and I'll get another two engines and do a side by side comparison :D


  2. How do you plan to ride the bike?

    I've read the mototune method... While many points he makes make a lot of sense, especially about changing the oil so early, to me, it seems a bit too aggressive for something that will be used purely on the road - unless you plan on caning it around everywhere.

    Is that engine one of those Zongzhen ones?
  3. mine is a 125 lifan.

    It'll be a commuter pretty much. Don't have time for racetrack stuff and not going to risk it on the road
  4. Its a 125. It's a single. The cost to change the engine is less than a major service on a normal bike. Break it in with a hammer and anvil if you want.
    • Like Like x 3
  5. but its my cost :D

    I've been told elsewhere that even if that method works the chinese engine probably won't have the close tolerances to make it worthwhile. I'll just run it in smoothly like I originally thought and go from there.
  6. dont baby a new engine,will do more harm than good, but dont thrash it either, ride it how it will be ridden in normal use, just make sure you keep varying the engine speed, & DONT let it sit idling
  7. A couple of bike dealers I know use the hard break in method for their demo bikes, one chap I know uses this method for his track bikes.

    As long as the oil is changed straight away e.g. after 20-30 mins hard and varied running it does more good then harm and ensures a good, tight mating of the rings.
    • Agree Agree x 1
  8. My admittedly inexperienced thoughts: The reason for break-in is to get a good seal. One theory is to wear down the high spots, scraping away deposits of worn-off metal and burnt run-in oil in the process. If it gets too hot you may get hard spots or burnt on deposits that take forever to wear down with a resultant poor seal in that area, maybe.

    If you only do an OK job what happens in the future? You don’t get maximum power and use more oil.

    So if you are commuting how often will you be using absolute maximum power? – Not very often even if you wring its throat regularly.

    How will you know if you aren’t getting as much power as you might have with the “Ideal break-In”? Really only by sticking it on a Dyno and compare it with an identical bike.

    Burning more oil? Probably only a problem if you’ve re-built an old motor yourself done a really bad job at honing and maybe stuffed up the rings. Maybe the engine dies at 250,000km rather than 300,000km, - which could have more to do with how it’s treated over the next decade.

    Having said that I’ve just brought a new Yamaha 150cc single 4-sroke and I’m following the Factory break-in instructions. Sort of also ‘cause I’ve only had my learners 3 days longer than I’ve had my bike so lots of stop-start, slow speed and general tootling around suits me & the motor to learn what to do. But I do have testosterone and the desire to see what happens if I go to 10,500 in all 6 gears is strong.

    So two different techniques but as long as you don’t let it get really hot for a few minutes then they are probably both valid.

    I've recently got rid of an '83 ALFA with >300,000ks that I swear was pumping unburnt oil straight out the exhaust.

  9. I broke in a 125cc yamaha scooter using the manufacturers recommendations.

    here are some things i noticed, my scooter was slower new than the demo i rode with a couple thousand km's on it.

    after the break in and and adding more km's to the bike it has gotten noticeably faster top speed when new 80ish top speed with a couple thousand km's on the odo 95-100ish, this is on the same course between home and work and my weight has not changed.

    when i serviced the scoot this came out of the oil (trapped in the filter)

    View attachment 17591 View attachment 17592 View attachment 17593

    during the run in I rode the bike normally with attention to a few details i followed the recommendations 1/3, 2/3 and then full throttle first 100km, 300km, then after 500km.

    i tried my best to avoid prolonged durations at the same RPM so instead of my 2-3km's down the motor way i took the back streets where i had more varied rpm starting and stopping.

    this is not to say i never used the motorway or gave it full throttle during the break in just tried to avoid it where possible.

    the scooter now goes hard, doesn't blow any smoke, valves only needed a small adjustment at 1000km, and it's not burning any oil, and i would say it is actually faster now than the demo i rode with the same amount of km's on it, and it would be safe to assume the demo was thrashed straight out of the crate up until i rode it.
  10. Eew what was that stuff? A bit of swarf from manufacturing and a bit of toe-nail?
  11. it was a bit of swarf, what looked like a bit of copper, a fragment that looked like it had chipped off a cast part, and a bunch of fillings.

    shows that the first oil change is important, while it all settled to the bottom of the sump and got caught buy the filter, it is probably the reason why the manufacturers advise not bouncing it off the rev limiter for the first couple hundred km's to give the engine a chance to have the crap flushed out.
  12. thanks guys. On the engine it has a "don't do more than 50kph during the break in period" sticker, but that is as far as it goes for manufacturers recommendations.

    So the standard is 1/3 throttle for 100kms, 1/2 until 300 then after 500 do what you want?

    By the time the bike is on the road I'll be going to work in town, so only about 3km's away in city traffic. Plenty of stop/start. Then afterwards it'll be back out to Brighton which is about 28km's so it'll be easy to do the 500km's just doing the work run. All stop/start traffic too.

    I should probably just get the bike on the road, do a 20km trip and change the oil immediately, then after another 50 change again and again at 300?

  13. this is from my scooter manual 4stroke 125

    I assume your new Lifan will arrive dry, so you will just be using the recommended motor oil, it probably only takes around 900ml, so if you buy a 4-5L bottle for $40 doing regular oil changes is not expensive.
  14. #14 Kernel, May 4, 2013
    Last edited: May 4, 2013
    That is pretty much how it should be done.

    Try and get it in top gear at low revs (without lugging it!) so you can open that throttle up and get plenty of fuel in there to really set those rings nicely. Let her sing! But don't cane the shit out of it either.

    But at the end of a day, as Lilley said... It's a chinese 125. Just ride it dude.

    That is not the optimal way to break in a new motor. Those guidelines are IMO only really there to stop idiots from injuring themselves on their brand new bike after they got their Learners yesterday, don't put all your faith in it.

    Others have said and I will reiterate... if you really want to look after this motor (I still think it's not a big deal for a little Lifan) keep changing the oil as soon as possible. Use the silly break-in guidelines in the manual as guidelines for when to change the oil. So change it at 100kms, then 300kms, then 500kms, then 1000kms, and then change it every 1000kms or earlier. If you wanted to be super anal you could change it at 1500kms, then 2000kms and then change it every 1000kms or earlier. The Mototune guy reckons, use Petroleum based car oil without any of those friction motors (which you do not want regardless) then once the engine is broken in, switch to your favourite oil. So probably switch to whatever oil you want to use at 2000kms.
  15. +1 for that. Mineral based oils are suited to older engines with much wider tolerances. With the "loose" seal of new rings modern synthetics won't do such a good job of the initial seal and scraping of the high spots. So if you really want to bother, good mineral based oil for the initial fill. As to the grade this is where my knowledge runs out.

  16. I think Penrite has a JASO-MA approved 15w40 mineral based oil at a very reasonable price. I've used it in the DR650, no problems with it.
  17. #17 AdamA, Jun 18, 2014
    Last edited by a moderator: Jun 18, 2014
    Hey all,

    I have a new 675 being delivered this weekend and after much research, I've decided to go with a, I'll say a medium break in. A break in between a hard and the manual version. The bike has 2km's on it.

    But I wanted to see if anyone else out there has gone against what the manual said and done a more aggressive break in on their brand new bike, and what their thoughts are after doing so.
    I'm not so much chasing the increase horse power, which is nice, but more so longevity and reliability.

    A break down of my plan is;

    1. Have a mineral based oil in it, warm up to operating temp and ride it for about 15km's in city traffic (unavoidable) to the open roads going up and down the gears, and in between, half throttle bursts of 2000 rpm to 4000 rpm in probably 2nd gear only, using only engine braking as much as possible.
    2. Turn off the bike and let it cool down for 20mins or so. (read this was important due to any high friction points needing to be cooled down)
    3. Warm up if needed and another 2okm's of the above using 2000 rpm to 5000 rpm. Cool down.
    3. Same as above using 2000 rpm to 6000 rpm for another 20km's.
    4. Oil and filter change while engine is still warm.
    5. Warm up to op. temp. Same as before but now 3000k to 7000 rpm for 20km's, then cool down.
    6. For every 20km's or so here on I will add 1000rpm to the top and maybe a few bursts adding 1000 rpm to the bottom too.
    7. Once I hit 10000 rpm which should be around the 140km's mark, I'll throw in a couple of harder, but brief, acceleration up to 12000 rpm and 13000 rpm (red lines at 14500 rpm) but not too many.
    8. Another oil and filter change at probably 150km - 200km's.
    9. From here on, I guess I will ride it normally with a few harder revs to 12000 - 14000 rpm every now and then until 1000km's which I believe will be the first service.
    10. Continue on in the same fashion, maybe with some full throttle bursts until it is considered broken in which is 1500km's or 3000km's? I'll check the manual when I get it.
    11. Lastly switch to Synthetic Oil.

    Good idea? Bad idea? Suggests some changes? Have you done this before?
    Love to hear your thoughts.

    Cheers all.

    <mod-edit> Wrong forum (General) & discussed many times already. Thread moved & merged *sighs*
    • Funny Funny x 1
  18. #18 AdamA, Jun 18, 2014
    Last edited by a moderator: Jun 19, 2014
    Sorry my mistake. Should of known to put my question/query in a 15 month old thread that's been discussed many times.

    That conversation is 15months old. But it's not your fault, nor mine.

    I am curious, do you know what the difference is or just heard there is a difference? I Hope I don't get a Chinese lunch time special.
  19. bit over board with the oil changes, and good luck riding it at 2000rpm.
    just run it at manufacturers recommendations or a little harder
  20. Triumph recommended break-in is an absolute joke (at least 2013 model). It basically says baby engine as much as you can. BS.
    You need to load/unload engine constantly. Use 1/2 or 3/4 trev range. DO NOT ride first 100km at 2000rpms - that won't help the engine at all.
    You overcomplicate everything with your steps. Simply don't baby it.
    But do it sensibly too (don't take to the red line). But above all - don't sit at constant RPMs for a long time.