I have switched to an 11t engine sprocket and have experienced 3 sprocket failures so far….some within 4-15 minute sessions. Has anyone experienced this issue? It has a plastic plain bearing that just looks cheezy in comparison with the cage needle bearing one on the 12t. I put Motul chain lube on every 15 minute session and put a little extra on the spindle nut. I have also noticed that my new style clutch by the end of the day chatters which it never used to do when I ran the 12t. I have to take the drum off and sand off the deposits on the inside, and I also sand off the clutch itself to smooth it out. My supplier says its a manufacturer defect but want to make sure it might not be something else you guys might know about.
Are you using the correct outer washer and nut ? We have seen a number of failures from using the wrong outer washer and nut which may interfere with the chain and sprocket.. I would suggest putting it together and taking a hard look at it to ensure that it is running clean, free of interference… rotate it by hand and I think you will see the problem. We have run 11t drivers with great success.