The motor will last longer if it's broke in my way compared to being pussyfooted. I don't wanna argue with you but there is a reason why the pros do it this way, and it's not because they wanna tear the thing apart to rebuild it. The fact is during break in you need to put a high load on the piston rings. This load on the rings cause them to expand and "mate" better to the cylinder surface. And by running a motor at a low rpm during break in isn't putting enough load on the rings to be broke in right. I'm not saying to run at a constant high rpm because that's the total wrong way, but if you want your motor to run the best you need to ride it hard. If you have goodluck with your way of breaking a motor in more power to you, but all I'm saying is my way is the RIGHT way.[img]i/expressions/face-icon-small-smile.gif[/img]

 

but my question was how long do you run it till before you change the oil or till its brokin in

 

just go out and pin it thats wat i did 2 my KFX it runs great still

 

You obviously are not a mechanical engineer and you truly don't understand metallurgy.

Nascar engine builders do put fresh engines through it's paces during break in but for short periods of time. And like I said they tear down every engine they build after every race. The ideal Nascar engine would run 500 miles then blow up.
2 stroke race teams also beak in their engines the same way but for very short periods of time, ie. less than 20 seconds. They'll hold the engine wide open then shut it down.
To break in a motor correctly you should occasionally bring it to red line and back down. Do this for 15-20 minutes of riding to get the engine up to temperature then let it coll for about 20 minutes. You should then do it again but this time take it for a longer ride, 30-40 minutes and once again shut it down and let it cool. Doing this 3-4 times will allow the metal engine components to go through heat cycles, some people call it "seasoning". Doing this prevents you from overstressing the fresh metal which will reduce the chances of warping softer meatls like aluminum.
Class dismissed!

 

what kind of oil should i use after break in. Yamaha oil or would something else work or work better

 

u dont need 2 change ur oil

 

You're right! I said go through the gears and deaccelarate. And I forgot to mention that the first 20 min is very important. You're taking me all wrong here. I'm not saying to run it wide open all day, but bring it up to redline like you said off and on. And heat cycles are fine too. But you have no right to say I don't know what I'm talking about. My Dad and i used to run a service shop and my Dad is OMC and Mercury certified. He taught me everything he knows so I do know a thing or two. So I sure the hell know what it takes to break a motor in right. But I found the harder you run them WHILE USING THE SAME PRINCIPAL the better they run.

 

Honestly, after the first tank of gas I would change the oil and filter. That will get rid of any assembly lube they might have used and you'll also be drainig out any metal filings/shavings that are common in new motors.
I'd use regular oil for the first few changes then I'd switch to synthetic. I personally prefer Castrol and Mobil. I currently use Castrol R4 superbike synthetic. I use it in my streetbikes and noticed a huge difference in clutch feel/action when I made the switch to synthetic.

 

Pushinthelimit,
I shouldn't have got on you like that. I reacted to your first post "The harder you ride it during break in the better it will run".
I just don't want this guy to go out and rail the throttle and have the piston start smacking the valves.
He was looking for advice and I wrote what I have done with numerous vehicles with excellent success. Streetcars, musclecars, motorcycles and atv's I've built them all.
I learned how to and how not to the hard way. The Jeep wasn't the only vehicle I tried to break in using the abuse method, my Firebird was also a victim. Wiping out a set of rings and scoring the cylinder can be costly mistake.

 

I believe in this same basic principle
I gave my raptor and my truck hell when I first got them.......and now they are faster than most of the others alike.........may be a coincidence but I think not.........