PDA

View Full Version : comparison: 400ex vs yfz engine



cals400ex
04-24-2004, 12:32 PM
well a few of my buddies now are running yfzs so i figured i would have a little test and tell you how they compare to my bike. i didn't get to ride it but by just watching it run you can figure a lot out. currently i am running a 10.8:1 ross, stage 2, x-6, jetting, etc.

we first start up the bikes. it is clearly easy to tell the yfz starts easier. it can be dead cold out and all you have to do is put the choke on and hit the start button and it won't die once it is started. where i am over there holding the gas so it won't die right when the bike is just started.

when racing, you can tell the yfz is geared much higher. down low it doesn't have the hit that my ex has. 1st gear, i pull. 2nd gear about even. 3rd gear he starts to pull. 4th he pulls harder. by the time we were into 5th gear, he was about 4-5 bikes in front. this kid on the yfz wasn't totally use to his bike yet so he probably could have beat me a little worse.


durability, well we don't know the bike is new. i can tell you nothing went wrong or not even a little flaw occured the whole night with the yfz.

overall, the yfz is a really nice bike. it runs really nice and has a powerband feel. for instance, he would be even with me or pulling about as hard as me for a second and then he would just jump a bike length in front like nothing. then we would even out and once again he would jump a bike length a few seconds later. this bike jumped really well and seemed to have a good wheelie balance.
i actually thought i was going to get smoked worse than i did. we had a pretty even launch and made sure of that so we could compare the bike and not the best launches as i would have beat him since he isn't use to the bike totally.


my buddy traded in a raptor for his yfz. i was shocked but the piped raptor had more top speed than the yfz by a little bit. however, through the gears the rap couldn't keep up. through the gears the yfz took a piped predator too. we didn't get to top speed here but just shifted into 5th gear and the yfz definately had the edge up to that point.

would i consider buying a yfz? you bet. i expected it to be what it was or maybe even a little more from what i read. all in all it seemed like a really nice bike and didn't have the unwanted rattles that the predator has and it had a better feel when just sitting on the bike.


could i get my ex beating a yfz? oh yeah. i was expecting to get smoked a little worse. however, it would take some work to get there. by the time you put this work in the ex i don't know if it would still be more reliable than a newer more technological bike. plus you have the advantage with liquid cooling with the yami. i think i will still keep my ex though and make it a sleeper. :eek: