Proper break-in procedure

[DerrD25]

I did a full engine rebuild (top and bottom end) on a yz85. I was told to break it in hard or however my riding style is after letting it warm up and no sustained throttle, till its up to temp. Then let it cool completely down and to do this three times.

Another way I was told to break it in was to not at all break it in hard. I was told warm it up, go through the heat cycles and gradually go through gears on each cycle

And the last way I was told was to not do either one of the other two ways but to just start it up, and go through heating cycles by reving it(which doesn't makes sense at all)

So which is the best way to break-in a completely new motor? Thanks

[JuggernuatRider]

Everyone has their own ways, and you are going to get million different ways. There are tons of threads on this already, so just take your pick. I just rebuilt my kx250 and did 2 heat cycles and then rode it like I usually did. Good luck

[NoFiddyPilot]

Ron Hamp knows more about this than 99% of us...

https://www.thumpertalk.com/wiki/_/how-to-break-in-an-engine-r283

[bobsled]

I have always heard to do the 2nd one listed...advice given to me from my bike mechanic friends. After you have done the three gentle/moderate rides (making sure to go through the gears) I'm told you can pretty much ride balls out.

I have no source to cite...other than advice of the guys at the shop when I watched them rebuild a kx100

[fulton246]

I did a full engine rebuild (top and bottom end) on a yz85. I was told to break it in hard or however my riding style is after letting it warm up and no sustained throttle, till its up to temp. Then let it cool completely down and to do this three times.

Another way I was told to break it in was to not at all break it in hard. I was told warm it up, go through the heat cycles and gradually go through gears on each cycle

And the last way I was told was to not do either one of the other two ways but to just start it up, and go through heating cycles by reving it(which doesn't makes sense at all)

So which is the best way to break-in a completely new motor? Thanks

I know there are some people that say to ride it hard, but I wouldn't follow that advice. A good analogy is to think of your body and all of its moving parts. What are you supposed to do before you work out or exercise? Stretch... Your engine has a lot of moving parts and needs to do the same thing. Here is a short, but good read that discusses different techniques for breaking in a new engine: http://www.motosport.com/blog/breaking-bad-how-to-break-in-a-dirt-bike-engine

[NoFiddyPilot]

I know there are some people that say to ride it hard, but I wouldn't follow that advice. A good analogy is to think of your body and all of its moving parts. What are you supposed to do before you work out or exercise? Stretch... Your engine has a lot of moving parts and needs to do the same thing. Here is a short, but good read that discusses different techniques for breaking in a new engine: http://www.motosport.com/blog/breaking-bad-how-to-break-in-a-dirt-bike-engine

 

Who is Andrew T and why is he worth listening to? He might be awesome, but no idea who he is, so a fair question.

 

Also, https://www.thumpertalk.com/blog/5/entry-106-dont-stretch-prior-to-exercise/ Def challenges the long held beliefs on stretching.

[Wild Alaskan]

Break it in riding slow, fast or heat cycles, it make basically zero difference. The latter two waste more of your time however.

[speedtoad]

I can tell you what my owner's says, but I can't image what would happen if they told all their new bike owners to ride the bike hard through all the gears.  A lawyers worst nightmare.

[KcDavis]

I know there are some people that say to ride it hard, but I wouldn't follow that advice. A good analogy is to think of your body and all of its moving parts. What are you supposed to do before you work out or exercise? Stretch... 

 

Stretching before any exercise can actually hinder your performance.  Holding stretches for any extended period of time can tire out your muscles.  It is actually better to do lower intensity exercises to warm up and do full on stretching once your workout is complete.  Stretching is good, but not necessarily important before a work out.

Edited January 30, 2015 by KcDavis

[ScootMcGoot]

Your going to get a million answers on this topic but here is what I personally do. If I am just replacing a top end I prefer a hard break in to ensure a good ring seal. My procedure is usually 3 hard 15 minute runs after completely warming up the engine with no throttle and then letting it cool down completely between the 15 minute runs. After the 3 runs I change the oil and ride as I normally would from then on out.

When breaking in a lower end as well as a top end I don't do a hard break in. Follow the same basic steps except I take it easy on the throttle.

[DerrD25]

Your going to get a million answers on this topic but here is what I personally do. If I am just replacing a top end I prefer a hard break in to ensure a good ring seal. My procedure is usually 3 hard 15 minute runs after completely warming up the engine with no throttle and then letting it cool down completely between the 15 minute runs. After the 3 runs I change the oil and ride as I normally would from then on out.

When breaking in a lower end as well as a top end I don't do a hard break in. Follow the same basic steps except I take it easy on the throttle.

makes sense,, thanks