i was reading, and saw some pic proof, that with 4strokes, warm them up properly first(when u first start it)when the engine is finally warm, start riding how you would normally ride, when you do this, the piston rings will seat properly, since at first the cylinder walls aren't totaly smooth, and when you ride pretty hard, with a load on the engine, the rings will properly seat, if you take it too easy at first, you will loose that roughness on the cylinder wall and loose the opportunity to seat the piston rings properly. reason the manual says to break them in easily, is to reduce the amount of warrenty claims.

 

Tekky....you need to take some automotive classes to understand how a motor breaks in. If the manufactures print the break-in info just to have less warranty claims, then tell me this, why do they print the same thing in ...a dirtbikes manual??? Only Yamaha & KTM offer warranty & it's only for 30 days. Honda, Kawasaki, Suzuki don't give you warranty...sold as is. Breaking them in hard as some of you guys do won't make your bike break, but the motor will last longer if you break it in by the book.

 

You said it not me.....[img]i/expressions/face-icon-small-shocked.gif[/img]

I still to this day have seen the atv's I have sold and none of them have had any problems that could have occurred from riding it hard. Except my Rod on my Raptor, but now I am finding out it was due to improper jetting.

I am just suggesting my opinion here, you dont have to believe me nor accept it.

 

my pops taught me to break a bike/car in like you WANT it to drive. Drive it like you stole it! Yeah, I rode my rappy hard at first. I got the Grizz up to 65mph with only a few hours on the clock. I'll do the same with my YFZ [img]i/expressions/face-icon-small-happy.gif[/img]

 

break in

 

Hey, I was right !![img]i/expressions/face-icon-small-happy.gif[/img]!!

I mean, my builders were right!!

Well written I should say.

Thank you Stebob!!

 

i got my info from mototuneUSA...every quad/dirtbike i have owned, i broke the engine in that way, and from my experience, they lasted a nice long while. The reason i think that the manuals say that...is some people might just buy the bikes brand new, not let the engines warm up, hog on the gas for the first ride on a cold engine, and wonder why there engines siezed/broke and then they would go back to the dealer and whine and bitch about it. I have had good experience with this technique, also on that site, interesting way he does his porting...he increases the amount of volumn, instead of the actual port size, interesting reading. I might have to try that


also....why did you mention i should take some automotive classes? where am i mistaken?

 

I've taken (actually was sent..employee training)automotive mechanic classes, & like the ones I had taken in high school they all go through a break-in schedule chapter in the class. All I'm trying to say is that what I've been taught & trained over the years is what I believe. It's fine if you guys "break em in like you're gonna ride em" but from what I've been taught over the years is what I believe....not what some shop or motor builder tells me to do. That's all.

 

Ive read too many different things. All ive established is that its good to rev it part way (no more than 75%) through the rev range then let it coast back down.

 

This is the third new yfz 450 Ive heard of blowing up. My buddies lost a crank bearing.

good thing for those reliable, long lasting 4 strokes...