Advantages/disadvantages to the auto clutch rpm settings

[aeffertz]

I've always just had it set at 5000 RPM from the factory but just tried ripping around with it at 0 but didn't really notice a difference. I ride the 2-strokes in the game so I'm always clutching it out of corners naturally. If I tried to go from a dead stop without revving it up and dumping the clutch, it was obviously slower to get up and go but otherwise I didn't really notice much of a difference.

So that left me wondering, are there any advantages to having it set at 0 rather than 5000? It's probably all mental but the 125 almost feels faster with it at 0 but I'm probably just imagining things. It definitely feels different, though. Almost more like an actual 125 engine.

What's the low down on this setting? I've searched but didn't really find what I was looking for.

[yzmxer608]

If you don't use the clutch, just start at a stop and slowly apply throttle, the auto RPM is the RPM at which the bike will start moving (automatically releases the clutch). On a 125 with it set to 0 it'll bog like hell since you got no power down low. Normally the small bikes is best to have it at 5k since they don't make much power in lower rpms, the only bikes it may help having it lower is the bigger ones where lugging can help. But as you said on a 125 you manually use the clutch so much you don't really notice it.

[aeffertz]

For some reason the 250 seems to slide out less/handle better with the auto RPMs at a lower setting. I dunno if this is accurate or not but it feels like it!

[SOAB_465]

I get the same feeling. I run it at 2500-3000 depending on the traction for the 250. If you let it get to 5000 before it locks up it is pretty violent

[yzmxer608]

Depends on gearing too, if you use a higher ratio that's less snappy you probably won't notice it as much. I've really only ridden the YZ250 though, so I can't comment on the other powerbands.

[ShackAttack12]

Think of the auto clutch as the point where your rider will drop the clutch. There will be more immediate torque at 5000rpms vs 3000rpms,

I made a crude dyno chart comparing the bikes:


At 3000/5000 rpms, the bikes roughly produce the following HP:
YZ125: 2/8
YZ250F: 2/10
YZ250: 4/15
YZ450F: 5/18

By lowering the autoclutch on the more powerful bikes, you are essentially allowing the power to roll in more softly. In the case of the 450, instead of abruptly sending 18hp to the wheels you're rolling in power starting at 5hp.