'06 YZ450 Drive Sprocket Nut Size

[jschwalbe]

I've got a buddy coming over to help me replace the original sprockets and chain - anyone know the exact size of the drive sprocket nut? I'd like to make sure he brings the correct size. Also - any tips on removing the phillips head screws holding on the chain cover - they must have some locktite applied.

Thanks in advance...

[grayracer513]

27 mm, same as the rear axle nut. 1 1/16" if you don't have the metric size.

On the sproket, flat side goes out.

[matt4x4]

Put a phillips screwdriver firmly seated and squared up into the screw, tap it with a hammer as you twist the screwdriver left - should loosen right up.

[jschwalbe]

Thanks much...

[DPW]

Put a phillips screwdriver firmly seated and squared up into the screw, tap it with a hammer as you twist the screwdriver left - should loosen right up.

What I do is "Put a phillips screwdriver(the correct size so it fits snug) firmly seated and squared up into the screw" and then put vise grips on the handle of the screwdriver and use the vise grips to turn the screwdriver keeping a palm on the end of the screwdriver to keep it seated...

[Wiz636]

Put a phillips screwdriver firmly seated and squared up into the screw, tap it with a hammer as you twist the screwdriver left - should loosen right up.

I remove those micky mouse screws and cover and replace them with hex head bolts.

[grayracer513]

The real solution is an impact screwdriver.

I remove those micky mouse screws and cover and replace them with hex head bolts.

Me too.

[husqy360]

just got a new front sprocket and you guys helpet me alot.!

[jschwalbe]

Got the cover off - the tapping definitely helped. Can't get the nut off of the drive sprocket. My buddy brought over a portable impact wrench and socket - we applied over 100 Nm of torque and the thing wouldn't budge. We also were sure to bend the tab down on the safety washer. We then tried the old fashioned socket wrench and couldn't move the thing at all - even with one of us holding the brake and the bike (along with a screw drive through the rear sprocket to keep the wheel from turning). The manual indicates that this should be set at 54 Nm - so what are we missing?

[grayracer513]

You are going counterclockwise (left), aren't you?

[jschwalbe]

Yep - we ultimately used a 2.5 ft cheater pipe attached to the drive sprocket - took one of us to hold the bike down but the nut finally broke lose - also had to use a pipe through the rear wheel to keep it from moving. Must have been put on incorrectly at the dealer or factory...

[grayracer513]

Rust never sleeps.

[Wiz636]

Rust never sleeps.

Yep, that is one of the few places on bikes nowadays that will rust. Hit it with a shot of WD-40 after each wash or ride. I do that to my chain also, then when it dries I put on the chain lube.