Front sprocket question

[sharpmarble]

I'm putting new sprockets on my bros YZ426, what size is the nut on the front sprocket?

Help me out, I put forth this question in my forum but apparently no one has heard of this!!!!

[MotoGoalie]

It's really big. Its about a 26 or 27mm on a 03 YZ450f.

[jamieyz426f01]

its a 28mm on the 426 mine was a right pain to get off, it would have been easier with an impact driver!.

[grayracer513]

Twenty-seven millimeter.

[99YZ400F]

27mm, is that the same as on a 99 400F? (not to hijack your thread or anything)

[grayracer513]

Might be. It's the same on both my YZF's and all the other later YZ's I've popped 'em off of.

[flintlock28]

Is the screw a normal right hand thread, or is it reverse????

Don

[426panzer]

Not a reverse thread...

[flintlock28]

Thanks for the info, panzer.............

[copsey]

Right hand threads. It's a 27 back to 97 and possibly earlier if I remember correctly. I know the 2000+ are 27's.

[jamieyz426f01]

yea sry bout that it is a 27mm

[sirthumpalot]

Normal thread. Air wrench takes it right off (leave the tranny in neutral), or leave the chain on and have a buddy stand on the rear brake while you loosen it with a wrench.

Almost forgot; don't forget to pick up a spare flat lock washer for the front sprocket. It's a flat washer and after you tighten the nut you have to bend it over the nut to keep it from loosening. They usually have several sides that can be bent so you can reuse it once, but if it has already been reused then you'll need a new one.