YZ450F Break In

2 replies to this topic
  • OcotilloRcr07

Posted October 23, 2006 - 11:23 AM


07 Brand new off the floor, checked all nuts/bolts.. Threw some lock-tite on my sprocket bolts and few other spots. Ive got rougly 3-4 hours on it... Changed the oil&filter / cleaned air filter etc etc.. The first 3-4 hours the bike could idle for about 1 1/2 minutes before heating was an issue, now the bike idles about 30-45 seconds and pipe starts to turn cherry red, is that because im past break-in period? could this be a jetting issue? Or is it simply normal, since its a race bike? Obviously constant airflow cools the motor, but I would assume these bikes should be able to idle from cold for atleast a minute.

After break in period, what would be some good steps to take towards good maint.+

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  • Ranger18

Posted October 23, 2006 - 12:28 PM


Did your dealer do the first step of the break in?
My dealer fired the bike up and let it run for 5 or 10 minutes. While it was running the pipe turned cherry, then the bike over heated, and they shut it down. After that I did my break in ride, as described in the manuel. The pipe hasn't turned cherry since, not even on a 110 degree day. You might want to rejet, but the jetting isn't so bad that it will cause it to overheat in 30 sec. Also is it just your pipe glowing, or is your bike overheating after 30 sec?

Some other advise would be to keep an eye on you grease (wheel bearings, link, ext.), keep an eye on your chain tension (stock chain sucks, but if you don't have any chain adjusted properly it will stretch out) Other than that just follow the manuel.

  • grayracer513

Posted October 23, 2006 - 01:53 PM


If you want to have some fun, search for "pipe glows red", and check out the number of times people new to the bike post this. It is completely normal, although new YZF's do tend to be a little lean on delivery. What causes this is the aggresive, late closing exhaust cam timing, the retarded timing at idle in neutral, and the fact that the header is titanium, and only about .040" thick or less.

They also don't care to be idled more than a minute or so, since they don't get any air over the radiators, and don't circulate water very rapidly at idle.

Don't worry about it. Lots of people have the same problem

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