All I can say is after 24 years of owning and riding, I have never had any problems following my method. If yours works, AMEN brother. I was always taught not to baby it but don't abuse it, and keep your RPMs fluctuating.

 

if u have to tear one dowm right after the break in , do u got to do it again

 

From my under standing anytime you put a new piston or rings in you have to break it in.

 

well its still the same rings & piston , bout the end orf my breakin period a spring broke on my shift shaft & i had to tear it all down & split the case , ive bout got it back together & was wonderin if i had to do it again

 

There is a post in the Honda forum, from a guy who bought a new Rancher 420 and broke it in "easy". His buddy had one that got broken in "hard". The guy who broke in easy, was asking why his was way down on power compared to his friends! Hum.....sloppy rings, low compression???

All my machines get broken in doing badass hillclimbs. Several are going on 10 years old and a huge number of hours, and all still run like the day they were new!

The reason your owner's manual recommends an easy breakin, is liability! What would happen if a manufacturer recommended you run it hard, and you crashed the new bike that you aren't yet familiar with? Everybody would sue them! They would rather have you down on power than have to deal with you in court.

 

I see that the BelRay link I posted above isn't working. I will try to repost it if it gets working. Some good info there.....

All the 450's with their little slipper pistons, tolerate a lot of compression blow-by. That means that fuel mixture will rapidly contaminate your oil (diluting it out), and that is why you need to do frequent oil changes on all the 450's.

Think about it....if your rings are tight it's going to minimize this, but if they are sloppy because you broke it in easy....it is going to be even worse!

 

The one main thing an engine builder will say is make sure you keep the RPMs varied.... in other words, don't go on a long 3 hour ride where you are cruising at the same constant RPM during break in...... so with that in mind the best thing is to hit the track or trails hard....... the constant on/off of the throttle of MX racing is what those 450s are made for so that is how they should be broken in too....

 

<div class="FTQUOTE"><begin quote>Originally posted by: ss97

The one main thing an engine builder will say is make sure you keep the RPMs varied.... in other words, don't go on a long 3 hour ride where you are cruising at the same constant RPM during break in...... so with that in mind the best thing is to hit the track or trails hard....... the constant on/off of the throttle of MX racing is what those 450s are made for so that is how they should be broken in too....</end quote></div>

I follow this religiously, as well as cool down periods, but only after I have seated the rings properly doing hillclimbs/downhills!!! This need not be done at excessive speed or high rpm, but the load does need to be high. The only real requirement is that you get that compression maxed out so you spread those rings and they wear into the cylinder wall. This is why hillclimbs/downhills work so great for this.....

 

<div class="FTQUOTE"><begin quote>Originally posted by: reconranger

<div class="FTQUOTE"><begin quote>Originally posted by: ss97



The one main thing an engine builder will say is make sure you keep the RPMs varied.... in other words, don't go on a long 3 hour ride where you are cruising at the same constant RPM during break in...... so with that in mind the best thing is to hit the track or trails hard....... the constant on/off of the throttle of MX racing is what those 450s are made for so that is how they should be broken in too....</end quote></div>



I follow this religiously, as well as cool down periods, but only after I have seated the rings properly doing hillclimbs/downhills!!! This need not be done at excessive speed or high rpm, but the load does need to be high. The only real requirement is that you get that compression maxed out so you spread those rings and they wear into the cylinder wall. This is why hillclimbs/downhills work so great for this.....</end quote></div>

That explanation makes more sense to me. When i think hill climb, I think low gear pinned. I do run my machine hard, not as hard as normal, but I do not baby it.

 

On a new engine to seat the rings, I do hillclimbs (three runs up and down) each day, then cool it off completely overnight. (Fortunately, I have multiple monster hillclimbs all around where I live!). I do this for about a week....you have to be patient!

Then I just do normal trail riding at slow to medium speed and varied throtle, for a few hours to break in the bearings. After that, I do trail riding at medium to high speed for a few hours, but again varying the throtle. Then a switch to ester synthetic oil and good to go. Has worked great for me for many years!!!