The sprocket with the additional flange / shoulder is the correct fitment. A sprocket without the flange will cause the sprocket and especially the chain to become too close to the engine casing and that will allow the chain to mash up the bolts on the casing situated behind the sprocket and at the upper rear of the casing. Also the sprocket without the flange / shoulder will not allow the sprocket nut to tighten down on it (tab washer included) . This will allow the none flange sprocket to float on the shaft behind the nut and not run in the correct alignment.

Great idea to machine down an old sprocket to create the required spacer but it would have to be perfectly flat otherwise the sprocket nut will not be able to apply the 120Nm torque required to the entire contact surface of the sprocket, plus it would have to be the exact width as to allow the tab washer just about to fit on the end of the gearbox shaft.


I found this out myself two days ago when I decided to put my new chain and sprox on, which I had in my personal stock for a while, only to find the new front sprocket was plain so I've had to order a new one.

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I have a lot of growing up to do. I realized that the other day inside my fort.