New engine break-in - What do you think about this article?

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earwig · #1 Unread post by **earwig** » Thu Mar 09, 2006 1:04 pm

This guy basically says to ignore the manual's reccomendation for breaking in any 4 stroke engine... and run it HARD as apposed to "an easy break in"... anyone have any thoughts or opinions? http://www.mototuneusa.com/break_in_secrets.htm

ZooTech · #2 Unread post by **ZooTech** » Thu Mar 09, 2006 1:09 pm

I've read the owner's manual, and the article you linked to, and I feel something in the middle is really best. I believe the owner's manual was written by liability attorneys, and I believe the article was written by a well-meaning but radical guy. The most important thing is to not race the motor right away, but to vary the RPM's as much as possible in order to keep the rings under a load.

earwig · #3 Unread post by **earwig** » Thu Mar 09, 2006 1:18 pm

I let my idiotic brother take my new bike out (it only has abuot 115 miles on it) and he did 105mph breifly ... i found this article searching for someting that might explain what doing crazy speeds liek that might do to the engine during break-in... do you think its possible that he could have screwed something up? I always follow the easy break in on my bikes etc.

ZooTech wrote:I've read the owner's manual, and the article you linked to, and I feel something in the middle is really best. I believe the owner's manual was written by liability attorneys, and I believe the article was written by a well-meaning but radical guy. The most important thing is to not race the motor right away, but to vary the RPM's as much as possible in order to keep the rings under a load.

ZooTech · #4 Unread post by **ZooTech** » Thu Mar 09, 2006 1:19 pm

I wouldn't lose an ounce of sleep over it. The engine was under load to achieve that speed, and that's a good thing. Now, letting people borrow your bike..........

DivideOverflow · Thu Mar 09, 2006 1:24 pm

Your bike is supposed to be under load, just not over-revved. They want you to accelerate and push the bike.. just under a certain rpm for a certain number of miles.
If you go a little over is it going to kill it? No. The first 50 miles are the most important from what I have read. Although, it is good to still vary your speem for quite some time while breaking it in.

paul246 · #6 Unread post by **paul246** » Thu Mar 09, 2006 3:10 pm

I agree with the article and that is how I did the initial run on our last 2 new bikes.

The key thing is to pressurize the rings under load, briefly, let off to create a low pressure in the head and allow fresh oil to move upward. Accelerate aggressively again, let off again. Nothing is sustained, never over-rev, and be sure you have a safe place to do this, you don't want a cage coming up your butt when you are decellerating.

Its all over in 20 minutes or so, because that is about all the time you are going to get from the honing marks on the cylinder walls. The rings should now be bedded in properly and will remain so under load. Carry on with varied speed riding (city riding is best for this) for the remainder of the break-in period.

BuzZz · #7 Unread post by **BuzZz** » Thu Mar 09, 2006 7:51 pm

I agree with Paul and Motoman. Not just from what I've read, and there are many other sources who recommend the same method, by the fact I rebuild engines, run them 24/7 for 5-8 years, then strip them down and rebuild them again has proven to me that it works.

Break in a fresh motor properly, and it runs 5-8 years. Break it in 'gently' and it's back in my shop bay in 2-3 years. And it was a troublesome pile-a-krap when it was running in the fleet.

As Zoo said, you want the engine pulling a load, not really screaming at full rpm, but you can pull it to redline briefly periodically. And vary the load/unload cycles with little unloaded running in between.